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Lebenbaum M, de Oliveira C, Gagnon F, Laporte A. Child health and its effect on adult social capital accumulation. HEALTH ECONOMICS 2024; 33:844-869. [PMID: 38236659 DOI: 10.1002/hec.4792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 11/15/2023] [Accepted: 11/28/2023] [Indexed: 04/04/2024]
Abstract
Although studies have demonstrated important effects of poor health in childhood on stocks of human and health capital, little research has tested economic theories to investigate the effect of child health on social capital in adulthood. Studies on the influence of child health on adult social capital are mixed and have not used sibling fixed effects models to account for unmeasured family and genetic characteristics, that are likely to be important. Using the Add-Health sample, health in childhood was assessed as self-rated health, the occurrence of a physical health condition or mental health condition, while social capital in adulthood was measured as volunteering, religious service attendance, team sports participation, number of friends, social isolation, and social support. We used sibling fixed effects models, which attenuated several associations to non-significance. In sibling fixed effects models there was significant positive effects of greater self-rated health on participation in team sports and social support, and negative effect of mental health in childhood on social isolation in adulthood. These results suggest that children with poor health require additional supports to build and maintain their stock of social capital and highlight further potential benefits to efforts that address poor child health.
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Affiliation(s)
- Michael Lebenbaum
- Institute of Health Policy, Management and Evaluation (IHPME), University of Toronto, Toronto, Ontario, Canada
- Canadian Centre for Health Economics, Toronto, Ontario, Canada
- Center for Demography of Health and Aging, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Claire de Oliveira
- Institute of Health Policy, Management and Evaluation (IHPME), University of Toronto, Toronto, Ontario, Canada
- Canadian Centre for Health Economics, Toronto, Ontario, Canada
- Centre for Health Economics and the Hull York Medical School, University of York, York, UK
- Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - France Gagnon
- The Dalla Lana School of Public Health (DLSPH), University of Toronto, Toronto, Ontario, Canada
| | - Audrey Laporte
- Institute of Health Policy, Management and Evaluation (IHPME), University of Toronto, Toronto, Ontario, Canada
- Canadian Centre for Health Economics, Toronto, Ontario, Canada
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2
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Pekkurnaz D. Causal effect of obesity on the probability of employment in women in Turkey. ECONOMICS AND HUMAN BIOLOGY 2023; 51:101301. [PMID: 37651829 DOI: 10.1016/j.ehb.2023.101301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 07/11/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023]
Abstract
This study aims to investigate the causal effect of obesity on the employment probability of women in Turkey via the instrumental variable approach by using data from the 2018 Turkey and Demographic Health Survey. Obesity prevalence in the area of living and the overweight status of the oldest child, which are the most common types of instruments seen in the literature, are used as instruments. Consistent with the OLS result, the 2SLS estimate indicates that obese women are statistically significantly less likely to be employed when the overweight status of the child is used as an instrument. On the other hand, the statistically significant effect of obesity disappears when the area level obesity prevalence is used as the instrument. In addition, obesity in women decreases the likelihood of employment in the services sector and full-time jobs and employment with social security. Although the results of this study do not indicate the source of the effect found, the presence of a causal relationship for women should not be ignored when the economic burden of obesity for Turkey is considered.
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Affiliation(s)
- Didem Pekkurnaz
- Başkent University, Faculty of Economics and Administrative Sciences, Department of Economics, Bağlıca Campus, Fatih Sultan Mahallesi, Eskişehir Yolu 18. Km, Etimesgut, 06790 Ankara, Turkey.
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3
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Lenzen S, Gannon B, Rose C, Norton EC. The relationship between physical activity, cognitive function and health care use: A mediation analysis. Soc Sci Med 2023; 335:116202. [PMID: 37713774 DOI: 10.1016/j.socscimed.2023.116202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 07/27/2023] [Accepted: 08/30/2023] [Indexed: 09/17/2023]
Abstract
Physical activity is known to provide substantial health benefits and subsequently reduce health care use among older people, but little is known about how much of this effect is due to improved cognitive function as opposed to physical improvements in health. We study the direct and indirect effect of physical activity on health care use using the word recall task as a measure of cognitive function in a mediation framework. We use data from eight waves of the US Health and Retirement Study (HRS) (2004 - 2018) of people aged 65 and older and exploit genetic variations between individuals as an instrumental variable (IV) for cognitive function, a local health care supply measure as IV for health care use, and neighbourhood physical activity as IV for individual physical activity in our simultaneous three-equation model. We find small but negative direct and indirect effects of physical activity through improved cognitive function on the probability to see a GP and being admitted to a hospital, as well as the number of GP visits and the hospital length of stay. Improved cognitive function explains between 5% to 17% of the total effect of physical activity on the reduction in health care use.
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Affiliation(s)
- Sabrina Lenzen
- Centre for the Business and Economics of Health, Sir Llew Edwards Building (Building 14), Level 5, Room 513a, The University of Queensland, Faculty of Business, Economics and Law, QLD, St Lucia 4072, Australia.
| | - Brenda Gannon
- Centre for the Business and Economics of Health, Sir Llew Edwards Building (Building 14), Level 5, Room 513a, The University of Queensland, Faculty of Business, Economics and Law, QLD, St Lucia 4072, Australia; School of Economics, Colin Clark Building (Building 39), The University of Queensland, Faculty of Business, Economics and Law, QLD, St Lucia 4072, Australia.
| | - Christiern Rose
- School of Economics, Colin Clark Building (Building 39), The University of Queensland, Faculty of Business, Economics and Law, QLD, St Lucia 4072, Australia.
| | - Edward C Norton
- Department of Health Management and Policy, University of Michigan, M3108 SPH II 1415 Washington Heights Ann Arbor, MI 48109-2029, United States of America; Department of Economics, University of Michigan, United States of America; Population Studies Center, United States of America; National Bureau of Economic Research, United States of America.
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4
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Yu B, Zachrisson HD, Cheesman R, Ystrom E, Nes RB. Boys with overweight status lagged behind girls with overweight status in reading: evidence from mendelian randomization. J Clin Epidemiol 2023; 159:199-205. [PMID: 37156340 DOI: 10.1016/j.jclinepi.2023.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 04/05/2023] [Accepted: 05/01/2023] [Indexed: 05/10/2023]
Abstract
OBJECTIVES We investigated the relationship between childhood weight status and academic achievement across sexes and different school subjects in Norway. STUDY DESIGN AND SETTING We used data from the Norwegian Mother, Father and Child Cohort Study (MoBa), which includes genetic data (N = 13,648, 8-year-old children). We employed within-family mendelian randomization, using a body mass index (BMI) polygenic risk score as an instrument to address unobserved heterogeneity. RESULTS Contrary to most previous findings, we observed that overweight status (including obesity) has more detrimental effects on reading achievement in boys than in girls; the test scores of boys with overweight were about a standard deviation lower than those of normal weight boys, and the negative effects on reading achievement became stronger in the later grade. CONCLUSION Previous obesity prevention studies have mainly targeted girls, based on the assumption that the obesity penalty is greater for girls. Our findings highlight that particular attention to boys with overweight may help reduce the existing gender gap in academic achievement.
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Affiliation(s)
- Baeksan Yu
- Department of Education, Gwangju National University of Education, Gwangju, South Korea.
| | | | - Rosa Cheesman
- PROMENTA Research Center, Department of Psychology, University of Oslo, Oslo, Norway
| | - Eivind Ystrom
- PROMENTA Research Center, Department of Psychology, University of Oslo, Oslo, Norway
| | - Ragnhild Bang Nes
- PROMENTA Research Center, Department of Psychology, University of Oslo, Oslo, Norway; Department of Mental Health and Suicide, Norwegian Institute of Public Health, Oslo, Norway; Department of Philosophy, Classics, and History of Arts and Ideas, University of Oslo, Oslo, Norway
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5
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Hartwig FP, Wang L, Davey Smith G, Davies NM. Average Causal Effect Estimation Via Instrumental Variables: the No Simultaneous Heterogeneity Assumption. Epidemiology 2023; 34:325-332. [PMID: 36709456 DOI: 10.1097/ede.0000000000001596] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Instrumental variables (IVs) can be used to provide evidence as to whether a treatment has a causal effect on an outcome . Even if the instrument satisfies the three core IV assumptions of relevance, independence, and exclusion restriction, further assumptions are required to identify the average causal effect (ACE) of on . Sufficient assumptions for this include homogeneity in the causal effect of on ; homogeneity in the association of with ; and no effect modification. METHODS We describe the no simultaneous heterogeneity assumption, which requires the heterogeneity in the - causal effect to be mean independent of (i.e., uncorrelated with) both and heterogeneity in the - association. This happens, for example, if there are no common modifiers of the - effect and the - association, and the - effect is additive linear. We illustrate the assumption of no simultaneous heterogeneity using simulations and by re-examining selected published studies. RESULTS Under no simultaneous heterogeneity, the Wald estimand equals the ACE even if both homogeneity assumptions and no effect modification (which we demonstrate to be special cases of-and therefore stronger than-no simultaneous heterogeneity) are violated. CONCLUSIONS The assumption of no simultaneous heterogeneity is sufficient for identifying the ACE using IVs. Since this assumption is weaker than existing assumptions for ACE identification, doing so may be more plausible than previously anticipated.
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Affiliation(s)
- Fernando Pires Hartwig
- Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom
| | - Linbo Wang
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada
| | - George Davey Smith
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Neil Martin Davies
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU, Norwegian University of Science and Technology, Norway
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Kawaguchi D, Lee J, Lin MJ, Yokoyama I. Is Asian flushing syndrome a disadvantage in the labor market? HEALTH ECONOMICS 2023. [PMID: 37088538 DOI: 10.1002/hec.4675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 01/16/2023] [Accepted: 03/03/2023] [Indexed: 05/03/2023]
Abstract
A large fraction of people in East Asia are incapable of digesting alcohol because of a genetic deficiency. This study examines whether the variation in alcohol tolerance contributes to inequality in the labor market. We conduct our original surveys in Japan, Taiwan, and Korea with the measurement of respondents' degree of alcohol tolerance by a bio-marker test. We find that alcohol-tolerant men consume significantly more alcohol, but their earnings and hours worked do not differ from those of alcohol-intolerant men. Despite a prevalent view that drinking alcohol is indispensable to establish good relationships with colleagues and business partners, our results suggest that there is no systematic impact of alcohol tolerance on labor market outcomes.
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Affiliation(s)
| | - Jungmin Lee
- Department of Economics, Seoul National University, Gwanak-gu, Seoul, Korea
| | - Ming-Jen Lin
- Department of Economics, National Taiwan University, Taipei, Taiwan
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Cawley J, Han E, Kim J, Norton EC. Genetic nurture in educational attainment. ECONOMICS AND HUMAN BIOLOGY 2023; 49:101239. [PMID: 36996576 DOI: 10.1016/j.ehb.2023.101239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 12/21/2022] [Accepted: 03/15/2023] [Indexed: 05/08/2023]
Abstract
Health is strongly and positively correlated with education, which is one of many reasons to better understand the determinants of education. In this paper, we test for a specific type of family influence on education: genetic nurture. Specifically, we test whether a person's educational attainment is correlated with their sibling's polygenic score (PGS) for education, controlling for their own PGS. Models estimated using data from the National Longitudinal Survey of Adolescent to Adult Health (Add Health) yield strong evidence of genetic nurture; a two-standard deviation increase in a sibling's genetic predisposition to higher education is associated with a 13.6% point increase in the probability that the respondent has a college degree. Evidence of genetic nurture is robust to alternative measures of educational attainment and different measures of the polygenic score. An exploration of mechanisms suggests that omission of parental PGS explains no more than half of the estimated effect, and that the magnitude of the genetic nurture varies with the characteristics of the sibling.
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Kurniansyah N, Wallace DA, Zhang Y, Yu B, Cade B, Wang H, Ochs-Balcom HM, Reiner AP, Ramos AR, Smith JD, Cai J, Daviglus M, Zee PC, Kaplan R, Kooperberg C, Rich SS, Rotter JI, Gharib SA, Redline S, Sofer T. An integrated multi-omics analysis of sleep-disordered breathing traits implicates P2XR4 purinergic signaling. Commun Biol 2023; 6:125. [PMID: 36721044 PMCID: PMC9889381 DOI: 10.1038/s42003-023-04520-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/23/2023] [Indexed: 02/01/2023] Open
Abstract
Sleep Disordered Breathing (SDB) is a common disease associated with increased risk for cardiometabolic, cardiovascular, and cognitive diseases. How SDB affects the molecular environment is still poorly understood. We study the association of three SDB measures with gene expression measured using RNA-seq in multiple blood tissues from the Multi-Ethnic Study of Atherosclerosis. We develop genetic instrumental variables for the associated transcripts as polygenic risk scores (tPRS), then generalize and validate the tPRS in the Women's Health Initiative. We measure the associations of the validated tPRS with SDB and serum metabolites in Hispanic Community Health Study/Study of Latinos. Here we find differential gene expression by blood cell type in relation to SDB traits and link P2XR4 expression to average oxyhemoglobin saturation during sleep and butyrylcarnitine (C4) levels. These findings can be used to develop interventions to alleviate the effect of SDB on the human molecular environment.
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Affiliation(s)
- Nuzulul Kurniansyah
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
| | - Danielle A Wallace
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
| | - Ying Zhang
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
| | - Bing Yu
- Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Brian Cade
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Heming Wang
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Heather M Ochs-Balcom
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Alexander P Reiner
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, NY, USA
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - Alberto R Ramos
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joshua D Smith
- Northwest Genomic Center, University of Washington, Seattle, WA, USA
| | - Jianwen Cai
- Department of Biostatistics, University of North Carolina, at Chapel Hill, NC, USA
| | - Martha Daviglus
- Institute for Minority Health Research, University of Illinois at Chicago, Chicago, IL, USA
| | - Phyllis C Zee
- Division of Sleep Medicine, Department of Neurology, Northwestern University, Chicago, IL, USA
| | - Robert Kaplan
- Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Department of Epidemiology & Population Health, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Charles Kooperberg
- Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Sina A Gharib
- Computational Medicine Core, Center for Lung Biology, UW Medicine Sleep Center, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Susan Redline
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Tamar Sofer
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, USA.
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA.
- Departments of Medicine and of Biostatistics, Harvard University, Boston, MA, USA.
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9
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Menta G, Lepinteur A, Clark AE, Ghislandi S, D'Ambrosio C. Maternal genetic risk for depression and child human capital. JOURNAL OF HEALTH ECONOMICS 2023; 87:102718. [PMID: 36565586 DOI: 10.1016/j.jhealeco.2022.102718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
We here address the causal relationship between the maternal genetic risk for depression and child human capital using UK birth-cohort data. We find that an increase of one standard deviation (SD) in the maternal polygenic risk score for depression reduces their children's cognitive and non-cognitive skill scores by 5 to 7% of a SD throughout adolescence. Our results are robust to a battery of sensitivity tests addressing, among others, concerns about pleiotropy and dynastic effects. Our Gelbach decomposition analysis suggests that the strongest mediator is genetic nurture (through maternal depression itself), with genetic inheritance playing only a marginal role.
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Affiliation(s)
- Giorgia Menta
- Luxembourg Institute of Socio-Economic Research (LISER), Luxembourg
| | | | - Andrew E Clark
- University of Luxembourg, Luxembourg; Paris School of Economics - CNRS, France
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10
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Chen C, Wang P, Zhang RD, Fang Y, Jiang LQ, Fang X, Zhao Y, Wang DG, Ni J, Pan HF. Mendelian randomization as a tool to gain insights into the mosaic causes of autoimmune diseases. Clin Exp Rheumatol 2022; 21:103210. [PMID: 36273526 DOI: 10.1016/j.autrev.2022.103210] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 10/06/2022] [Accepted: 10/11/2022] [Indexed: 12/14/2022]
Abstract
Autoimmune diseases (ADs) are a broad range of disorders which are characterized by long-term inflammation and tissue damage arising from an immune response against one's own tissues. It is now widely accepted that the causes of ADs include environmental factors, genetic susceptibility and immune dysregulation. However, the exact etiology of ADs has not been fully elucidated to date. Because observational studies are plagued by confounding factors and reverse causality, no firm conclusions can be drawn about the etiology of ADs. Over the years, Mendelian randomization (MR) analysis has come into focus, offering unique perspectives and insights into the etiology of ADs and promising the discovery of potential therapeutic interventions. In MR analysis, genetic variation (alleles are randomly dispensed during meiosis, usually irrespective of environmental or lifestyle factors) is used instead of modifiable exposure to explore the link between exposure factors and disease or other outcomes. Therefore, MR analysis can provide a valuable method for exploring the causal relationship between different risk factors and ADs when its inherent assumptions and limitations are fully considered. This review summarized the recent findings of MR in major ADs, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), and type 1 diabetes mellitus (T1DM), focused on the effects of different risk factors on ADs risks. In addition, we also discussed the opportunities and challenges of MR methods in ADs research.
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Affiliation(s)
- Cong Chen
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - Peng Wang
- Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China; Teaching Center for Preventive Medicine, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China
| | - Ruo-Di Zhang
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - Yang Fang
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - Ling-Qiong Jiang
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - Xi Fang
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - Yan Zhao
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China
| | - De-Guang Wang
- Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China; Department of Nephrology, The Second Hospital of Anhui Medical University, Hefei, China.
| | - Jing Ni
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China.
| | - Hai-Feng Pan
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei 230032, Anhui, China; Institute of Kidney Disease, Inflammation & Immunity Mediated Diseases, The Second Hospital of Anhui Medical University, China.
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11
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Liu SS, Zhu Y. Simultaneous Maximum Likelihood Estimation for Piecewise Linear Instrumental Variable Models. ENTROPY (BASEL, SWITZERLAND) 2022; 24:e24091235. [PMID: 36141121 PMCID: PMC9497487 DOI: 10.3390/e24091235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/28/2022] [Accepted: 08/31/2022] [Indexed: 05/12/2023]
Abstract
Analysis of instrumental variables is an effective approach to dealing with endogenous variables and unmeasured confounding issue in causal inference. We propose using the piecewise linear model to fit the relationship between the continuous instrumental variable and the continuous explanatory variable, as well as the relationship between the continuous explanatory variable and the outcome variable, which generalizes the traditional linear instrumental variable models. The two-stage least square and limited information maximum likelihood methods are used for the simultaneous estimation of the regression coefficients and the threshold parameters. Furthermore, we study the limiting distribution of the estimators in the correctly specified and misspecified models and provide a robust estimation of the variance-covariance matrix. We illustrate the finite sample properties of the estimation in terms of the Monte Carlo biases, standard errors, and coverage probabilities via the simulated data. Our proposed model is applied to an education-salary data, which investigates the causal effect of children's years of schooling on estimated hourly wage with father's years of schooling as the instrumental variable.
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Affiliation(s)
- Shuo Shuo Liu
- Department of Statistics, The Pennsylvania State University, University Park, PA 16801, USA
- Correspondence:
| | - Yeying Zhu
- Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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12
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Cui Y, Si W, Zhu C, Zhao Q. Alcohol Consumption and Mild Cognitive Impairment: A Mendelian Randomization Study from Rural China. Nutrients 2022; 14:nu14173596. [PMID: 36079852 PMCID: PMC9460868 DOI: 10.3390/nu14173596] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 12/02/2022] Open
Abstract
Alcohol consumption has been associated with the risk of mild cognitive impairment (MCI) in observational studies. The result is inconsistent and whether the association is causal remains unknown. To examine the causal effect of alcohol consumption on MCI in rural China, this study used a cross-sectional dataset that included 1966 observations collected in rural China, of which 235 observations’ genotyping were collected. All participants accepted the MCI evaluation using Mini-Cog and were asked about the participants’ alcohol consumption behavior. The causal effect of alcohol consumption on MCI was investigated by Mendelian randomization (MR) of genetic variation in the aldehyde dehydrogenase 2 (ALDH2 rs671) gene. The risk of MCI in Chinese rural areas was 43%. Alcohol consumption was causally associated with a higher risk of MCI under MR design. Parameter estimates of drinking or not (b = 0.271, p = 0.007, 95% CI = 0.073 to 0.469), drinking frequency during the past 30 days (b = 0.016, p = 0.003, 95% CI = 0.005 to 0.027), and the weekly ethanol consumption (b = 0.132, p = 0.004, 95% CI = 0.042 to 0.223) were all positive and statistically significant at the 5% level. In conclusion, there was a high risk of MCI in rural China, and alcohol consumption was causally associated with a higher risk of MCI.
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Affiliation(s)
- Yi Cui
- College of Economics and Management, China Agricultural University, Beijing 100083, China
| | - Wei Si
- College of Economics and Management, China Agricultural University, Beijing 100083, China
- Academy of Global Food Economics and Policy, China Agricultural University, Beijing 100083, China
| | - Chen Zhu
- College of Economics and Management, China Agricultural University, Beijing 100083, China
- Academy of Global Food Economics and Policy, China Agricultural University, Beijing 100083, China
| | - Qiran Zhao
- College of Economics and Management, China Agricultural University, Beijing 100083, China
- Academy of Global Food Economics and Policy, China Agricultural University, Beijing 100083, China
- Correspondence:
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13
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Bankier S, Michoel T. eQTLs as causal instruments for the reconstruction of hormone linked gene networks. Front Endocrinol (Lausanne) 2022; 13:949061. [PMID: 36060942 PMCID: PMC9428692 DOI: 10.3389/fendo.2022.949061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
Hormones act within in highly dynamic systems and much of the phenotypic response to variation in hormone levels is mediated by changes in gene expression. The increase in the number and power of large genetic association studies has led to the identification of hormone linked genetic variants. However, the biological mechanisms underpinning the majority of these loci are poorly understood. The advent of affordable, high throughput next generation sequencing and readily available transcriptomic databases has shown that many of these genetic variants also associate with variation in gene expression levels as expression Quantitative Trait Loci (eQTLs). In addition to further dissecting complex genetic variation, eQTLs have been applied as tools for causal inference. Many hormone networks are driven by transcription factors, and many of these genes can be linked to eQTLs. In this mini-review, we demonstrate how causal inference and gene networks can be used to describe the impact of hormone linked genetic variation upon the transcriptome within an endocrinology context.
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Affiliation(s)
- Sean Bankier
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
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14
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Viinikainen J, Bryson A, Böckerman P, Kari JT, Lehtimäki T, Raitakari O, Viikari J, Pehkonen J. Does better education mitigate risky health behavior? A mendelian randomization study. ECONOMICS AND HUMAN BIOLOGY 2022; 46:101134. [PMID: 35354116 DOI: 10.1016/j.ehb.2022.101134] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Education and risky health behaviors are strongly negatively correlated. Education may affect health behaviors by enabling healthier choices through higher disposable income, increasing information about the harmful effects of risky health behaviors, or altering time preferences. Alternatively, the observed negative correlation may stem from reverse causality or unobserved confounders. Based on the data from the Cardiovascular Risk in Young Finns Study linked to register-based information on educational attainment and family background, this paper identifies the causal effect of education on risky health behaviors. To examine causal effects, we used a genetic score as an instrument for years of education. We found that individuals with higher education allocated more attention to healthy habits. In terms of health behaviors, highly educated people were less likely to smoke. Some model specifications also indicated that the highly educated consumed more fruit and vegetables, but the results were imprecise in this regard. No causal effect was found between education and abusive drinking. In brief, inference based on genetic instruments showed that higher education leads to better choices in some but not all dimensions of health behaviors.
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Affiliation(s)
- Jutta Viinikainen
- University of Jyväskylä, Jyväskylä University School of Business and Economics, Jyväskylä, Finland.
| | - Alex Bryson
- University College London, Social Research Institute, London, United Kingdom; National Institute of Economic and Social Research, London, United Kingdom; IZA Institute of Labor Economics, Bonn, Germany
| | - Petri Böckerman
- University of Jyväskylä, Jyväskylä University School of Business and Economics, Jyväskylä, Finland; IZA Institute of Labor Economics, Bonn, Germany; Labour Institute for Economic Research LABORE, Helsinki, Finland
| | - Jaana T Kari
- University of Jyväskylä, Jyväskylä University School of Business and Economics, Jyväskylä, Finland
| | - Terho Lehtimäki
- Tampere University, Department of Clinical Chemistry, Tampere, Finland; Fimlab Laboratories, Tampere, Finland; Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland; Tampere University, Finnish Cardiovascular Research Center, Tampere, Finland
| | - Olli Raitakari
- University of Turku and Turku University Hospital, Centre for Population Health Research, Turku, Finland; University of Turku, Research Centre of Applied and Preventive Cardiovascular Medicine, Turku, Finland; Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku, Finland
| | - Jorma Viikari
- University of Turku, Department of Medicine, Turku, Finland; Turku University Hospital, Division of Medicine, Turku, Finland
| | - Jaakko Pehkonen
- University of Jyväskylä, Jyväskylä University School of Business and Economics, Jyväskylä, Finland
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15
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de Leeuw C, Savage J, Bucur IG, Heskes T, Posthuma D. Understanding the assumptions underlying Mendelian randomization. Eur J Hum Genet 2022; 30:653-660. [PMID: 35082398 DOI: 10.1038/s41431-022-01038-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 12/06/2021] [Accepted: 01/04/2022] [Indexed: 11/09/2022] Open
Abstract
With the rapidly increasing availability of large genetic data sets in recent years, Mendelian Randomization (MR) has quickly gained popularity as a novel secondary analysis method. Leveraging genetic variants as instrumental variables, MR can be used to estimate the causal effects of one phenotype on another even when experimental research is not feasible, and therefore has the potential to be highly informative. It is dependent on strong assumptions however, often producing biased results if these are not met. It is therefore imperative that these assumptions are well-understood by researchers aiming to use MR, in order to evaluate their validity in the context of their analyses and data. The aim of this perspective is therefore to further elucidate these assumptions and the role they play in MR, as well as how different kinds of data can be used to further support them.
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Affiliation(s)
- Christiaan de Leeuw
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, The Netherlands.
| | - Jeanne Savage
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, The Netherlands
| | - Ioan Gabriel Bucur
- Department of Data Science, Institute for Computing and Information Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Tom Heskes
- Department of Data Science, Institute for Computing and Information Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Danielle Posthuma
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, The Netherlands.,Department of Clinical Genetics, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
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16
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Onyimadu O, Violato M, Astbury NM, Jebb SA, Petrou S. Health Economic Aspects of Childhood Excess Weight: A Structured Review. CHILDREN (BASEL, SWITZERLAND) 2022; 9:461. [PMID: 35455505 PMCID: PMC9028108 DOI: 10.3390/children9040461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/11/2022] [Accepted: 03/16/2022] [Indexed: 11/17/2022]
Abstract
An economic perspective is crucial to understand the broad consequences of childhood excess weight (CEW). These can manifest in the form of elevated health care and societal costs, impaired health status, or inefficiencies in the allocation of resources targeted at its prevention, management, or treatment. Although existing systematic reviews provide summaries of distinct economic research strands covering CEW, they have a restricted focus that overlooks relevant evidence. The overarching aim of this structured review was to update and enhance recent key reviews of four strands of economic evidence in this area, namely, (1) economic costs associated with CEW, (2) health utilities associated with CEW, (3) economic evaluations of interventions targeting CEW, and (4) economic determinants and broader consequences of CEW. Our de novo searches identified six additional studies for the first research strand, five studies for the second, thirty-one for the third, and two for the fourth. Most studies were conducted in a small number of high-income countries. Our review highlights knowledge gaps across all the research strands. Evidence from this structured review can act as data input into future economic evaluations in this area and highlights areas where future economic research should be targeted.
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Affiliation(s)
- Olu Onyimadu
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK; (O.O.); (N.M.A.); (S.A.J.)
| | - Mara Violato
- Nuffield Department of Population Health, University of Oxford, Old Road Campus, Oxford OX3 7LF, UK;
| | - Nerys M. Astbury
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK; (O.O.); (N.M.A.); (S.A.J.)
| | - Susan A. Jebb
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK; (O.O.); (N.M.A.); (S.A.J.)
| | - Stavros Petrou
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK; (O.O.); (N.M.A.); (S.A.J.)
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17
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Hazewinkel AD, Richmond RC, Wade KH, Dixon P. Mendelian randomization analysis of the causal impact of body mass index and waist-hip ratio on rates of hospital admission. ECONOMICS AND HUMAN BIOLOGY 2022; 44:101088. [PMID: 34894623 PMCID: PMC8784824 DOI: 10.1016/j.ehb.2021.101088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 10/27/2021] [Accepted: 11/21/2021] [Indexed: 05/31/2023]
Abstract
We analyze how measures of adiposity - body mass index (BMI) and waist hip ratio (WHR) - causally influence rates of hospital admission. Conventional analyses of this relationship are susceptible to omitted variable bias from variables that jointly influence both hospital admission and adipose status. We implement a novel quasi-Poisson instrumental variable model in a Mendelian randomization framework, identifying causal effects from random perturbations to germline genetic variation. We estimate the individual and joint effects of BMI, WHR, and WHR adjusted for BMI. We also implement multivariable instrumental variable methods in which the causal effect of one exposure is estimated conditionally on the causal effect of another exposure. Data on 310,471 participants and over 550,000 inpatient admissions in the UK Biobank were used to perform one-sample and two-sample Mendelian randomization analyses. The results supported a causal role of adiposity on hospital admissions, with consistency across all estimates and sensitivity analyses. Point estimates were generally larger than estimates from comparable observational specifications. We observed an attenuation of the BMI effect when adjusting for WHR in the multivariable Mendelian randomization analyses, suggesting that an adverse fat distribution, rather than a higher BMI itself, may drive the relationship between adiposity and risk of hospital admission.
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Affiliation(s)
- Audinga-Dea Hazewinkel
- Population Health Sciences, Bristol Medical School, University of Bristol, UK; MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, UK.
| | - Rebecca C Richmond
- Population Health Sciences, Bristol Medical School, University of Bristol, UK; MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, UK
| | - Kaitlin H Wade
- Population Health Sciences, Bristol Medical School, University of Bristol, UK; MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, UK
| | - Padraig Dixon
- MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol, UK; Nuffield Department of Primary Care Health Sciences, University of Oxford, UK
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18
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Interaction-based Mendelian randomization with measured and unmeasured gene-by-covariate interactions. PLoS One 2022; 17:e0271933. [PMID: 35947639 PMCID: PMC9365161 DOI: 10.1371/journal.pone.0271933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/08/2022] [Indexed: 02/02/2023] Open
Abstract
Studies leveraging gene-environment (GxE) interactions within Mendelian randomization (MR) analyses have prompted the emergence of two similar methodologies: MR-GxE and MR-GENIUS. Such methods are attractive in allowing for pleiotropic bias to be corrected when using individual instruments. Specifically, MR-GxE requires an interaction to be explicitly identified, while MR-GENIUS does not. We critically examine the assumptions of MR-GxE and MR-GENIUS in the absence of a pre-defined covariate, and propose sensitivity analyses to evaluate their performance. Finally, we explore the effect of body mass index (BMI) upon systolic blood pressure (SBP) using data from the UK Biobank, finding evidence of a positive effect of BMI on SBP. We find both approaches share similar assumptions, though differences between the approaches lend themselves to differing research settings. Where a suitable gene-by-covariate interaction is observed MR-GxE can produce unbiased causal effect estimates. MR-GENIUS can circumvent the need to identify interactions, but as a consequence relies on either the MR-GxE assumptions holding globally, or additional information with respect to the distribution of pleiotropic effects in the absence of an explicitly defined interaction covariate.
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19
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Pehkonen J, Viinikainen J, Kari JT, Böckerman P, Lehtimäki T, Viikari J, Raitakari O. Birth weight, adult weight, and cardiovascular biomarkers: Evidence from the Cardiovascular Young Finns Study. Prev Med 2022; 154:106894. [PMID: 34801564 DOI: 10.1016/j.ypmed.2021.106894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/12/2021] [Accepted: 11/14/2021] [Indexed: 10/19/2022]
Abstract
This study quantifies the causal effect of birth weight on cardiovascular biomarkers in adulthood using the Cardiovascular Risk in Young Finns Study (YFS). We apply a multivariable Mendelian randomization (MVMR) method that provides a novel approach to improve inference in causal analysis based on a mediation framework. The results show that birth weight is linked to triglyceride levels (β = -0.294; 95% CI [-0.591, 0.003]) but not to low-density lipoprotein (LDL) cholesterol levels (β = 0.007; 95% CI [-0.168, 0.183]). The total effect of birth weight on triglyceride levels is partly offset by a mediation pathway linking birth weight to adult BMI (β = 0.111; 95% CI [-0.013, 0.234]). The negative total effect is consistent with the fetal programming hypothesis. The positive indirect effect via adult BMI highlights the persistence of body weight throughout a person's life and the adverse effects of high BMI on health. The results are consistent with previous findings that both low birth weight and weight gain increase health risks in adulthood.
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Affiliation(s)
- Jaakko Pehkonen
- School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland.
| | - Jutta Viinikainen
- School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Jaana T Kari
- School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Petri Böckerman
- School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland; Labour Institute for Economic Research, Helsinki, Finland; IZA, Bonn, Germany
| | - Terho Lehtimäki
- Department of Clinincal Chemistry, Tampere University, Finland; Fimlab Laboratoriot Oy Ltd, Tampere, Finland; Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Finnish Cardiovascular Research Center Tampere, Tampere University, Tampere, Finland
| | - Jorma Viikari
- Department of Medicine, University of Turku, Turku, Finland, Division of Medicine, Turku University Hospital, Turku, Finland
| | - Olli Raitakari
- Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland; Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland; Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
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20
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Amin V, Behrman JR, Fletcher JM, Flores CA, Flores-Lagunes A, Kohler HP. Genetic risks, adolescent health, and schooling attainment. HEALTH ECONOMICS 2021; 30:2905-2920. [PMID: 34472149 PMCID: PMC10676638 DOI: 10.1002/hec.4421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 06/04/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
We provide new evidence on the effect of adolescent health behaviors/outcomes (obesity, depression, smoking, and attention deficit hyperactivity disorder [ADHD]) on schooling attainment using the National Longitudinal Study of Adolescent to Adult Health. We take two different approaches to deal with omitted variable bias and reverse causality. Our first approach attends to the issue of reverse causality by estimating the effect of health polygenic scores (PGSs) on schooling. Second, we estimate the effect of adolescent health using sibling fixed-effects models that control for unmeasured genetic and family factors shared by siblings. We use the PGSs as additional controls in the sibling fixed-effects models to reduce concerns about residual confounding from sibling-specific genetic differences. We find consistent evidence across both approaches that being genetically predisposed to smoking and smoking regularly in adolescence reduces schooling attainment. Estimates for depression are more imprecise, but also suggest that a high genetic risk of depression and adolescent depression reduce schooling attainment. We find mixed evidence for ADHD. Our estimates suggest that having a high genetic risk for ADHD reduces grades of schooling, but we do not find any statistically significant negative effects of ADHD. Finally, we find no consistent evidence for a detrimental effect of obesity on schooling attainment.
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Affiliation(s)
- Vikesh Amin
- Department of Economics, Central Michigan University, Mt Pleasant, Michigan, USA
| | - Jere R. Behrman
- Department of Economics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- GLO, Essen, Germany
| | - Jason M. Fletcher
- Department of Sociology, La Follette School of Public Affairs, University of Wisconsin–Madison, Madison, Wisconsin, USA
- NBER, Cambridge, Massachusetts, USA
- IZA, Bonn, Germany
| | - Carlos A. Flores
- GLO, Essen, Germany
- Department of Economics, California Polytechnic State University, San Luis Obispo, California, USA
| | - Alfonso Flores-Lagunes
- GLO, Essen, Germany
- IZA, Bonn, Germany
- Department of Economics, Syracuse University, Syracuse, New York, USA
| | - Hans-Peter Kohler
- Department of Economics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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21
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Pehkonen J, Viinikainen J, Kari JT, Böckerman P, Lehtimäki T, Raitakari O. Birth weight and adult income: An examination of mediation through adult height and body mass. HEALTH ECONOMICS 2021; 30:2383-2398. [PMID: 34250692 DOI: 10.1002/hec.4387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 06/09/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
This paper examines the causal links between early human endowments and socioeconomic outcomes in adulthood. We use a genotyped longitudinal survey (Cardiovascular Risk in Young Finns Study) that is linked to the administrative registers of Statistics Finland. We focus on the effect of birth weight on income via two anthropometric mediators: body mass index (BMI) and height in adulthood. We find that (i) the genetic instruments for birth weight, adult height, and adult BMI are statistically powerful; (ii) there is a robust total effect of birth weight on income for men but not for women; (iii) the total effect of birth weight on income for men is partly mediated via height but not via BMI; and (iv) the share of the total effect mediated via height is substantial, of approximately 56%.
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Affiliation(s)
- Jaakko Pehkonen
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Jutta Viinikainen
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Jaana T Kari
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Petri Böckerman
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
- Labour Institute for Economic Research, Helsinki, Finland and IZA, Bonn, Germany
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Finnish Cardiovascular Research Center, Tampere, Finland
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Olli Raitakari
- Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
- Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland
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22
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Windmeijer F, Liang X, Hartwig FP, Bowden J. The confidence interval method for selecting valid instrumental variables. J R Stat Soc Series B Stat Methodol 2021. [DOI: 10.1111/rssb.12449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Frank Windmeijer
- Department of Statistics and Nuffield College University of Oxford Oxford UK
- MRC Integrative Epidemiology Unit University of Bristol Bristol UK
| | - Xiaoran Liang
- Department of Economics University of Bristol Bristol UK
| | - Fernando P. Hartwig
- MRC Integrative Epidemiology Unit University of Bristol Bristol UK
- Center for Epidemiological Research University of Pelotas Pelotas Brazil
| | - Jack Bowden
- MRC Integrative Epidemiology Unit University of Bristol Bristol UK
- College of Medicine and Health University of Exeter Exeter UK
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23
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Edwards CH, Bjørngaard JH, Minet Kinge J. The relationship between body mass index and income: Using genetic variants from HUNT as instrumental variables. HEALTH ECONOMICS 2021; 30:1933-1949. [PMID: 33993584 DOI: 10.1002/hec.4285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 03/29/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
Several studies have estimated effects of body mass index (BMI) on labour market outcomes, and these studies have mixed findings. A significant challenge has been to adequately control for omitted variables, selection, reverse causality, and measurement error. We examine the impact of BMI on income using genetic variants as instrumental variables for BMI. Individual-level pre-tax income from tax records was merged with health survey data containing measured height and weight, and data on genetic variants. The analyses were stratified by sex and a variety of methods were used to explore the sensitivity and validity of the instrumental variable (IV) strategy. For females we found that BMI had a negative effect on the logarithm of income. The effect estimated from the IV models (-0.02) was larger than the effect estimated from naïve ordinary least squares regressions (-0.01). For males, the coefficients for the effect of BMI on income were imprecise, and both positive and negative coefficients were estimated depending on the estimation method. Our results suggest that females are susceptible to reduced income levels following increased BMI.
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Affiliation(s)
| | - Johan Håkon Bjørngaard
- Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway
- Nord University, Faculty of Nursing and Health Sciences, Levanger, Norway
| | - Jonas Minet Kinge
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Health Management and Health Economics, Institute of Health and Society, University of Oslo, Oslo, Norway
- Centre for Disease Burden, Norwegian Institute of Public Health, Oslo, Norway
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24
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Giontella A, Lotta LA, Overton JD, Baras A, Minuz P, Melander O, Gill D, Fava C. Causal Effect of Adiposity Measures on Blood Pressure Traits in 2 Urban Swedish Cohorts: A Mendelian Randomization Study. J Am Heart Assoc 2021; 10:e020405. [PMID: 34120448 PMCID: PMC8403279 DOI: 10.1161/jaha.120.020405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Background Different adiposity traits may be causally related to hypertension in different ways. By using genetic variants as randomly allocated proxies for studying the effect of modifying adiposity traits, the Mendelian randomization approach can be used to investigate this. Methods and Results In this study, we used 4 different genetic risk scores (GRS; GRS-BMI565, GRS-WHR324, GRS-VAT208, GRS-BF81) including hundreds of single nucleotide polymorphisms associated with body mass index, waist-to-hip ratio, visceral adipose tissue, and body fat, respectively. These were applied as instrumental variables in Mendelian randomization analyses. Two Swedish urban-based cohort studies, the Malmö Diet and Cancer, and the Malmö Preventive 795Projects were used to obtain genetic association estimates with blood pressure (BP). In both the Malmö Preventive Projects and Malmö Diet and Cancer studies, except for that for body fat, all of the genetic risk scores were significantly associated with systolic BP and diastolic BP, but with different magnitudes. In particular, in both cohorts, each standard deviation increase in the genetic risk score made up by the 324 single nucleotide polymorphisms associated with waist-to-hip ratio was associated with doubling of the likelihood of hypertension prevalence at baseline. However, only the genetic risk score made up by the 565 SNPs associated with body mass index was significantly associated with hypertension incidence during 23.6±4.3 years of follow-up in the Malmö Preventive Project. Conclusions We support a causal link between genetically mediated adiposity, especially waist-to-hip ratio and body mass index, and BP traits including hypertension prevalence and, for the first time to our knowledge, hypertension incidence. The differences in magnitude between these associations might suggest different mechanisms by which different adiposity affects BP/hypertension and consequently may indicate that tailored interventions are needed to reduce cardiovascular risk.
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Affiliation(s)
- Alice Giontella
- Department of Medicine University of Verona Verona Italy.,Department of Clinical Sciences Clinical Research Center Lund University Malmö Sweden
| | | | | | | | | | - Pietro Minuz
- Department of Medicine University of Verona Verona Italy
| | - Olle Melander
- Department of Clinical Sciences Clinical Research Center Lund University Malmö Sweden.,Department of Emergency and Internal Medicine Skåne University Hospital Malmö Sweden
| | - Dipender Gill
- Department of Epidemiology and Biostatistics School of Public Health Imperial College London London United Kingdom.,Department of Clinical Pharmacology and Therapeutics St George's, University of London London United Kingdom
| | - Cristiano Fava
- Department of Medicine University of Verona Verona Italy.,Department of Clinical Sciences Clinical Research Center Lund University Malmö Sweden
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25
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Corlin L, Ruan M, Tsilidis KK, Bouras E, Yu YH, Stolzenberg-Solomon R, Klein AP, Risch HA, Amos CI, Sakoda LC, Vodička P, Rish PK, Beck J, Platz EA, Michaud DS. Two-Sample Mendelian Randomization Analysis of Associations Between Periodontal Disease and Risk of Cancer. JNCI Cancer Spectr 2021; 5:pkab037. [PMID: 34222791 PMCID: PMC8242136 DOI: 10.1093/jncics/pkab037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/10/2021] [Accepted: 03/30/2021] [Indexed: 12/12/2022] Open
Abstract
Background Observational studies indicate that periodontal disease may increase the risk of colorectal, lung, and pancreatic cancers. Using a 2-sample Mendelian randomization (MR) analysis, we assessed whether a genetic predisposition index for periodontal disease was associated with colorectal, lung, or pancreatic cancer risks. Methods Our primary instrument included single nucleotide polymorphisms with strong genome-wide association study evidence for associations with chronic, aggressive, and/or severe periodontal disease (rs729876, rs1537415, rs2738058, rs12461706, rs16870060, rs2521634, rs3826782, and rs7762544). We used summary-level genetic data for colorectal cancer (n = 58 131 cases; Genetics and Epidemiology of Colorectal Cancer Consortium, Colon Cancer Family Registry, and Colorectal Transdisciplinary Study), lung cancer (n = 18 082 cases; International Lung Cancer Consortium), and pancreatic cancer (n = 9254 cases; Pancreatic Cancer Consortia). Four MR approaches were employed for this analysis: random-effects inverse-variance weighted (primary analyses), Mendelian Randomization-Pleiotropy RESidual Sum and Outlier, simple median, and weighted median. We conducted secondary analyses to determine if associations varied by cancer subtype (colorectal cancer location, lung cancer histology), sex (colorectal and pancreatic cancers), or smoking history (lung and pancreatic cancer). All statistical tests were 2-sided. Results The genetic predisposition index for chronic or aggressive periodontitis was statistically significantly associated with a 3% increased risk of colorectal cancer (per unit increase in genetic index of periodontal disease; P = .03), 3% increased risk of colon cancer (P = .02), 4% increased risk of proximal colon cancer (P = .01), and 3% increased risk of colorectal cancer among females (P = .04); however, it was not statistically significantly associated with the risk of lung cancer or pancreatic cancer, overall or within most subgroups. Conclusions Genetic predisposition to periodontitis may be associated with colorectal cancer risk. Further research should determine whether increased periodontitis prevention and increased cancer surveillance of patients with periodontitis is warranted.
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Affiliation(s)
- Laura Corlin
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA
- Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, MA, USA
| | - Mengyuan Ruan
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA
| | - Konstantinos K Tsilidis
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - Emmanouil Bouras
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - Yau-Hua Yu
- Department of Periodontology, Tufts University School of Dental Medicine, Boston, MA, USA
| | | | - Alison P Klein
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA
| | - Harvey A Risch
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA
| | | | - Lori C Sakoda
- Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA
| | - Pavel Vodička
- Department of the Molecular Biology of Cancer, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Pai K Rish
- Laboratory Medicine and Pathology, The Colon Cancer Family Registry at Mayo Clinic, Rochester, MN, USA
| | - James Beck
- Department of Dental Ecology, University of North Carolina, Chapel Hill, NC, USA
| | - Elizabeth A Platz
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA for CCFR, CORECT, GECCO, ILCCO, PanScan, and PanC4
| | - Dominique S Michaud
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA
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Dick K, Schneider JE, Briggs A, Lecomte P, Regnier SA, Lean M. Mendelian randomization: estimation of inpatient hospital costs attributable to obesity. HEALTH ECONOMICS REVIEW 2021; 11:16. [PMID: 33990897 PMCID: PMC8122556 DOI: 10.1186/s13561-021-00314-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/02/2021] [Indexed: 05/13/2023]
Abstract
BACKGROUND Mendelian Randomization is a type of instrumental variable (IV) analysis that uses inherited genetic variants as instruments to estimate causal effects attributable to genetic factors. This study aims to estimate the impact of obesity on annual inpatient healthcare costs in the UK using linked data from the UK Biobank and Hospital Episode Statistics (HES). METHODS UK Biobank data for 482,127 subjects was linked with HES inpatient admission records, and costs were assigned to episodes of care. A two-stage least squares (TSLS) IV model and a TSLS two-part cost model were compared to a naïve regression of inpatient healthcare costs on body mass index (BMI). RESULTS The naïve analysis of annual cost on continuous BMI predicted an annual cost of £21.61 [95% CI £20.33 - £22.89] greater cost per unit increase in BMI. The TSLS IV model predicted an annual cost of £14.36 [95% CI £0.31 - £28.42] greater cost per unit increase in BMI. Modelled with a binary obesity variable, the naïve analysis predicted that obese subjects incurred £205.53 [95% CI £191.45 - £219.60] greater costs than non-obese subjects. The TSLS model predicted a cost £201.58 [95% CI £4.32 - £398.84] greater for obese subjects compared to non-obese subjects. CONCLUSIONS The IV models provide evidence for a causal relationship between obesity and higher inpatient healthcare costs. Compared to the naïve models, the binary IV model found a slightly smaller marginal effect of obesity, and the continuous IV model found a slightly smaller marginal effect of a single unit increase in BMI.
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Affiliation(s)
- Katherine Dick
- Avalon Health Economics, 26 Washington St. 2nd Floor, Morristown, NJ, 07960, USA.
| | - John E Schneider
- Avalon Health Economics, 26 Washington St. 2nd Floor, Morristown, NJ, 07960, USA
| | - Andrew Briggs
- Avalon Health Economics, 26 Washington St. 2nd Floor, Morristown, NJ, 07960, USA
- London School of Hygiene and Tropical Medicine, Keppel St, Bloomsbury, London, WC1E 7HT, UK
| | - Pascal Lecomte
- Novartis AG, WSJ - 210.15.30.23, CH-4056, Basel, Switzerland
| | | | - Michael Lean
- University of Glasgow, University Avenue, Glasgow, G12 8QQ, Scotland
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Iliou A, Mikros E, Karaman I, Elliott F, Griffin JL, Tzoulaki I, Elliott P. Metabolic phenotyping and cardiovascular disease: an overview of evidence from epidemiological settings. Heart 2021; 107:1123-1129. [PMID: 33608305 DOI: 10.1136/heartjnl-2019-315615] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 12/13/2022] Open
Abstract
Metabolomics, the comprehensive measurement of low-molecular-weight molecules in biological fluids used for metabolic phenotyping, has emerged as a promising tool to better understand pathways underlying cardiovascular disease (CVD) and to improve cardiovascular risk stratification. Here, we present the main methodologies for metabolic phenotyping, the methodological steps to analyse these data in epidemiological settings and the associated challenges. We discuss evidence from epidemiological studies linking metabolites to coronary heart disease and stroke. These studies indicate the systemic nature of CVD and identify associated metabolic pathways such as gut microbial cometabolism, branched-chain amino acids, glycerophospholipid and cholesterol metabolism, as well as activation of inflammatory processes. Integration of metabolomic with genomic data can provide new evidence for involved biochemical pathways and potential for causality using Mendelian randomisation. The clinical utility of metabolic biomarkers for cardiovascular risk stratification in healthy individuals has not yet been established. As sample sizes with high-dimensional molecular data increase in epidemiological settings, integration of metabolomic data across studies and platforms with other molecular data will lead to new understanding of the metabolic processes underlying CVD and contribute to identification of potentially novel preventive and pharmacological targets. Metabolic phenotyping offers a powerful tool in the characterisation of the molecular signatures of CVD, paving the way to new mechanistic understanding and therapies, as well as improving risk prediction of CVD patients. However, there are still challenges to face in order to contribute to clinically important improvements in CVD.
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Affiliation(s)
- Aikaterini Iliou
- Pharmacy, National and Kapodistrian University of Athens School of Health Sciences, Athens, Attica, Greece
| | - Emmanuel Mikros
- Pharmacy, National and Kapodistrian University of Athens School of Health Sciences, Athens, Attica, Greece
| | - Ibrahim Karaman
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
| | - Freya Elliott
- School of Medicine and Dentistry, Queen Mary University, London, UK
| | - Julian L Griffin
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Ioanna Tzoulaki
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.,Department of Hygiene and Epidemiology, University of Ioannina, Ioannina, Greece.,BHF Research Centre for Excellence, Faculty of Medicine, Imperial College London, London, UK
| | - Paul Elliott
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK .,BHF Research Centre for Excellence, Faculty of Medicine, Imperial College London, London, UK.,MRC Centre for Environment and Health, School of Public Health, Imperial College London, London, UK.,Imperial College Biomedical Research Centre, Imperial College London, London, UK
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Hughes A, Wade KH, Dickson M, Rice F, Davies A, Davies NM, Howe LD. Common health conditions in childhood and adolescence, school absence, and educational attainment: Mendelian randomization study. NPJ SCIENCE OF LEARNING 2021; 6:1. [PMID: 33398003 PMCID: PMC7782810 DOI: 10.1038/s41539-020-00080-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 10/19/2020] [Indexed: 05/30/2023]
Abstract
Good health is positively related to children's educational outcomes, but relationships may not be causal. Demonstrating a causal influence would strongly support childhood and adolescent health as important for education policy. We applied genetic causal inference methods to assess the causal relationship of common health conditions at age 10 (primary/elementary school) and 13 (mid-secondary/mid-high school) with educational attainment at 16 and school absence at 14-16. Participants were 6113 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). Exposures were symptoms of attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), depression, asthma, migraines and BMI. Genetic liability for these conditions and BMI was indexed by polygenic scores. In non-genetic, multivariate-adjusted models, all health conditions except asthma and migraines were associated with poorer attainment and greater school absence. School absence substantially mediated effects of BMI (39.9% for BMI at 13) and migraines (72.0% at 10), on attainment with more modest mediation for emotional and neurodevelopmental conditions. In genetic models, a unit increase in standardized BMI at 10 predicted a 0.19 S.D. decrease (95% CI: 0.11, 0.28) in attainment at 16, equivalent to around a 1/3 grade lower in all subjects, and 8.7% more school absence (95% CI:1.8%,16.1%). Associations were similar at 13. Genetic liability for ADHD predicted lower attainment but not more absence. Triangulation across multiple approaches supports a causal, negative influence on educational outcomes of BMI and ADHD, but not of ASD, depression, asthma or migraine. Higher BMI in childhood and adolescence may causally impair educational outcomes.
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Affiliation(s)
- Amanda Hughes
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, BS8 2BN, UK.
- Bristol Medical School, University of Bristol, Barley House, Oakfield Grove, Bristol, BS8 2BN, UK.
| | - Kaitlin H Wade
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, BS8 2BN, UK
- Bristol Medical School, University of Bristol, Barley House, Oakfield Grove, Bristol, BS8 2BN, UK
| | - Matt Dickson
- Institute for Policy Research, University of Bath, Bath, UK
| | | | | | - Neil M Davies
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, BS8 2BN, UK
- Bristol Medical School, University of Bristol, Barley House, Oakfield Grove, Bristol, BS8 2BN, UK
- Department of Public Health and Nursing, K.G. Jebsen Center for Genetic Epidemiology, NTNU, Norwegian University of Science and Technology, Trondheim, Norway
| | - Laura D Howe
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, BS8 2BN, UK
- Bristol Medical School, University of Bristol, Barley House, Oakfield Grove, Bristol, BS8 2BN, UK
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Segal AB, Huerta MC, Aurino E, Sassi F. The impact of childhood obesity on human capital in high-income countries: A systematic review. Obes Rev 2021; 22:e13104. [PMID: 33189097 DOI: 10.1111/obr.13104] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/17/2020] [Accepted: 06/26/2020] [Indexed: 02/06/2023]
Abstract
Current evidence of the impact of childhood obesity on human capital development does not point in a consistent direction, and its interpretation is challenging. We carried out a systematic review of studies from high-income countries that used robust causal inference approaches to assess the impact of childhood overweight and obesity on outcomes typically linked to human capital development in economics. Global Health, Medline and EconLit were used to search for peer-reviewed papers. Three reviewers independently assessed study quality using the Newcastle-Ottawa Scale. Nineteen papers representing 22 studies met the inclusion criteria. Included studies were categorized based on three components of human capital: cognitive performance (n = 18), measured through test scores; educational attainment (n = 3), through grade progression and college completion; and labour market outcomes (n = 1), through wages. We find that childhood overweight and obesity hinder education outcomes, with effects mostly observed at older ages of exposure measurement (12+ years). Girls with overweight and obesity experienced larger negative effects and more often than boys. Future research should elucidate the pathways through which childhood obesity impacts human capital development, to support policies that may mitigate those impacts, thus averting social costs that are currently widespread, increasing and unaccounted for.
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Affiliation(s)
- Alexa Blair Segal
- Centre for Health Economics & Policy Innovation, Imperial College Business School, London, UK
| | - M Carmen Huerta
- Centre for Health Economics & Policy Innovation, Imperial College Business School, London, UK
| | - Elisabetta Aurino
- Centre for Health Economics & Policy Innovation, Imperial College Business School, London, UK
| | - Franco Sassi
- Centre for Health Economics & Policy Innovation, Imperial College Business School, London, UK
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30
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Centorrino S, Florens JP. Nonparametric estimation of accelerated failure-time models with unobservable confounders and random censoring. Electron J Stat 2021. [DOI: 10.1214/21-ejs1921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
| | - Jean-Pierre Florens
- Toulouse School of Economics University of Toulouse Capitole Toulouse, France
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Pereira RD, Rietveld CA, van Kippersluis H. The Interplay between Maternal Smoking and Genes in Offspring Birth Weight. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.10.30.20222844. [PMID: 33173933 PMCID: PMC7654929 DOI: 10.1101/2020.10.30.20222844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is well-established that both the child's genetic endowments as well as maternal smoking during pregnancy impact offspring birth weight. In this paper we move beyond the nature versus nurture debate by investigating the interaction between genetic endowments and this critical prenatal environmental exposure - maternal smoking - in determining birth weight. We draw on longitudinal data from the Avon Longitudinal Study of Parents and Children (ALSPAC) study and replicate our results using data from the UK Biobank. Genetic endowments of the children are proxied with a polygenic score that is constructed based on the results of the most recent genome-wide association study of birth weight. We instrument the maternal decision to smoke during pregnancy with a genetic variant (rs1051730) located in the nicotine receptor gene CHRNA3. This genetic variant is associated with the number of cigarettes consumed daily, and we present evidence that this is plausibly the only channel through which the maternal genetic variant affects the child's birth weight. Additionally, we deal with the misreporting of maternal smoking by using measures of cotinine, a biomarker of nicotine, collected from the mother's urine during their pregnancy. We confirm earlier findings that genetic endowments as well as maternal smoking during pregnancy significantly affects the child's birth weight. However, we do not find evidence of meaningful interactions between genetic endowments and an adverse fetal environment, suggesting that the child's genetic predisposition cannot cushion the damaging effects of maternal smoking.
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Affiliation(s)
- Rita Dias Pereira
- Erasmus School of Economics, Erasmus University Rotterdam
- Tinbergen Institute
| | - Cornelius A. Rietveld
- Erasmus School of Economics, Erasmus University Rotterdam
- Tinbergen Institute
- Erasmus University Rotterdam Institute for Behavior and Biology, Erasmus University Rotterdam
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32
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McMartin A, Conley D. Commentary: Mendelian randomization and education–Challenges remain. Int J Epidemiol 2020; 49:1193-1206. [DOI: 10.1093/ije/dyaa160] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Affiliation(s)
- Andrew McMartin
- Department of Sociology and Office of Population Research, Wallace Hall, Princeton University, Princeton, NJ 08540, USA
| | - Dalton Conley
- Department of Sociology and Office of Population Research, Wallace Hall, Princeton University, Princeton, NJ 08540, USA
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33
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Determining causal relationships in leadership research using Machine Learning: The powerful synergy of experiments and data science. THE LEADERSHIP QUARTERLY 2020. [DOI: 10.1016/j.leaqua.2020.101426] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Song Q, Huang T, Song J, Meng X, Li C, Wang Y, Wang H. Causal associations of body mass index and waist-to-hip ratio with cardiometabolic traits among Chinese children: A Mendelian randomization study. Nutr Metab Cardiovasc Dis 2020; 30:1554-1563. [PMID: 32636122 DOI: 10.1016/j.numecd.2020.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 04/07/2020] [Accepted: 05/08/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND AIMS Body mass index (BMI) and waist-to-hip ratio (WHR) have been reported to be causally associated with cardiometabolic diseases in adults in European populations. However, this causality was less explored in East Asian populations and in children. Our study aimed to explore and compare the causal associations of general obesity (measured by BMI) and central obesity (measured by WHR) with cardiometabolic traits. METHODS AND RESULTS We performed a Mendelian randomization (MR) analysis in 2030 unrelated children from two independent case-control studies in Beijing, China. BMI-associated single nucleotide polymorphisms (SNPs) and WHR-SNPs identified by previous genome-wide association studies were used as genetic instruments to examine the casual associations of BMI and WHR with cardiometabolic traits, including glycemic traits, blood lipids, and blood pressure. Each 1-SD increase in BMI and WHR were significantly associated with 0.111 mmol/L and 0.110 mmol/L increase in log-transformed fasting insulin (FINS), 0.049 and 0.060 increase in log-transformed HOMA-β, 0.112 and 0.108 increase in log-transformed HOMA-IR, 0.009 mmol/L and 0.015 mmol/L increase in log-transformed triglyceride, and 15.527 mmHg and 7.277 mmHg increase in systolic blood pressure, respectively (all P < 0.05). The receiver operating characteristic curves showed that WHR had a stronger effect on FINS, HOMA-β, HOMA-IR, and triglyceride than BMI (all P < 0.05). CONCLUSIONS Using the MR method, we found that the genetic predisposition to higher BMI or WHR was associated with altered cardiometabolic traits in Chinese children. When compared with general obesity, central obesity might have stronger effects on glycemic traits and blood lipids among children.
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Affiliation(s)
- Qiying Song
- Department of Maternal and Child Health, School of Public Health, Peking University, Beijing, 100191, China
| | - Tao Huang
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China
| | - Jieyun Song
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing, 100191, China
| | - Xiangrui Meng
- Center for Global Health Research, Usher Institute of Population and Health Sciences and Informatics, University of Edinburgh, Scotland, UK
| | - Chenxiong Li
- Department of Maternal and Child Health, School of Public Health, Peking University, Beijing, 100191, China
| | - Yan Wang
- Department of Maternal and Child Health, School of Public Health, Peking University, Beijing, 100191, China
| | - Haijun Wang
- Department of Maternal and Child Health, School of Public Health, Peking University, Beijing, 100191, China.
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Amin V, Flores CA, Flores-Lagunes A. The impact of BMI on mental health: Further evidence from genetic markers. ECONOMICS AND HUMAN BIOLOGY 2020; 38:100895. [PMID: 32603998 PMCID: PMC9062912 DOI: 10.1016/j.ehb.2020.100895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/19/2020] [Accepted: 05/24/2020] [Indexed: 05/30/2023]
Abstract
We estimate the effect of BMI on mental health for young adults and elderly individuals using data from the National Longitudinal Study of Adolescent Health and the Health & Retirement Study. To tackle confounding due to unobserved factors, we exploit variation in a polygenic score (PGS) for BMI within two related econometric methods that differ in the assumptions they employ. First, we use the BMI PGS as an IV and adjust for PGSs for other factors (depression and educational attainment) that may invalidate this IV. We find a large statistically significant effect of BMI on mental health for the elderly: a 5 kg/m2 increase in BMI (a difference equivalent to moving from overweight to obese) increases the probability of depression by 29 %. In contrast, for young adults the IV estimates are statistically and economically insignificant. We show that IV estimates likely have to be interpreted as identifying a weighted average of effects of BMI on mental health mostly for compliers on the upper quantiles of the BMI distribution. Second, we use the BMI PGS as an "imperfect" IV and estimate an upper bound on the average treatment effect for the population. The estimated upper bounds are consistent with the conclusions from the IV estimates.
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Affiliation(s)
- Vikesh Amin
- Department of Economics, Central Michigan University, Sloan Hall 312, Mount Pleasant, MI 48859, United States.
| | - Carlos A Flores
- Department of Economics, Orfalea College of Business, California Polytechnic State University at San Luis Obispo, San Luis Obispo, CA 93407, United States.
| | - Alfonso Flores-Lagunes
- Department of Economics and Center for Policy Research, Maxwell School of Citizenship and Public Affairs, Syracuse University; Research Fellow IZA, and GLO, 426 Eggers Hall, Syracuse, NY 13244, United States.
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Brunello G, Sanz-de-Galdeano A, Terskaya A. Not only in my genes: The effects of peers' genotype on obesity. JOURNAL OF HEALTH ECONOMICS 2020; 72:102349. [PMID: 32619796 DOI: 10.1016/j.jhealeco.2020.102349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/08/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
We use data from three waves of Add Health to study the short- and long-run effects of high school peers' genetic predisposition to high BMI-measured by grade-mates' average BMI polygenic scores-on adolescent and adult obesity in the U.S. We find that, in the short-run, a one standard deviation increase in peers' average BMI polygenic scores raises the probability of obesity for females by 2.8% points, about half the size of the effect induced by a one standard deviation increase in one's own polygenic score. No significant effect is found for males. In the long-run, however, the social-genetic effect fades away, while the effect of one's own genetic risk for BMI increases substantially. We suggest that mechanisms explaining the short-run effect for females include changes in nutrition habits and a distorted perception of body size.
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Affiliation(s)
- Giorgio Brunello
- Department of Economics and Management, University of Padova, via del Santo 33, 35123 Padova, Italy; IZA, Germany.
| | - Anna Sanz-de-Galdeano
- IZA, Germany; CRES-UPF, Spain; FAE, Universidad de Alicante, Carretera de San Vicente s/n, 03080 San Vicente, Alicante, Spain.
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Slob EAW, Burgess S. A comparison of robust Mendelian randomization methods using summary data. Genet Epidemiol 2020; 44:313-329. [PMID: 32249995 PMCID: PMC7317850 DOI: 10.1002/gepi.22295] [Citation(s) in RCA: 261] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 08/22/2019] [Accepted: 03/11/2020] [Indexed: 01/20/2023]
Abstract
The number of Mendelian randomization (MR) analyses including large numbers of genetic variants is rapidly increasing. This is due to the proliferation of genome-wide association studies, and the desire to obtain more precise estimates of causal effects. Since it is unlikely that all genetic variants will be valid instrumental variables, several robust methods have been proposed. We compare nine robust methods for MR based on summary data that can be implemented using standard statistical software. Methods were compared in three ways: by reviewing their theoretical properties, in an extensive simulation study, and in an empirical example. In the simulation study, the best method, judged by mean squared error was the contamination mixture method. This method had well-controlled Type 1 error rates with up to 50% invalid instruments across a range of scenarios. Other methods performed well according to different metrics. Outlier-robust methods had the narrowest confidence intervals in the empirical example. With isolated exceptions, all methods performed badly when over 50% of the variants were invalid instruments. Our recommendation for investigators is to perform a variety of robust methods that operate in different ways and rely on different assumptions for valid inferences to assess the reliability of MR analyses.
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Affiliation(s)
- Eric A. W. Slob
- Erasmus School of EconomicsErasmus University RotterdamRotterdamThe Netherlands
- Erasmus University Rotterdam Institute for Behavior and BiologyRotterdamThe Netherlands
| | - Stephen Burgess
- Department of Public Health and Primary CareUniversity of CambridgeCambridgeUK
- MRC Biostatistics UnitUniversity of CambridgeCambridgeUK
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Sumner JA, Nishimi KM, Koenen KC, Roberts AL, Kubzansky LD. Posttraumatic Stress Disorder and Inflammation: Untangling Issues of Bidirectionality. Biol Psychiatry 2020; 87:885-897. [PMID: 31932029 PMCID: PMC7211139 DOI: 10.1016/j.biopsych.2019.11.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/21/2019] [Accepted: 11/04/2019] [Indexed: 12/27/2022]
Abstract
Posttraumatic stress disorder (PTSD) has increasingly been linked to heightened systemic inflammation. It matters whether this association is causal (and either bidirectional or unidirectional) or correlational. Investigators have hypothesized that chronic systemic low-grade inflammation may contribute to greater risk of developing PTSD after experiencing trauma and/or serve as a mechanism linking PTSD to adverse physical health outcomes. However, if the PTSD-inflammation relation is correlational, it may not warrant further research aimed at understanding inflammation as a PTSD risk factor or as a pathway linking PTSD with poor health. In this review, we first assess the longitudinal evidence related to PTSD and inflammation to understand more clearly the directionality and causal nature of this relation. Overall, few longitudinal studies rigorously assess the direction of the PTSD-inflammation relation. Some of the evidence indicates that elevated inflammation assessed pretrauma or in the acute aftermath of trauma increases risk for developing PTSD. Fewer studies evaluate the influence of PTSD on subsequent inflammation levels, and findings are mixed. Sample characteristics and study designs, and also the type of inflammation-related measure, vary widely across studies. Based on current evidence, we then recommend several statistical and study design approaches that may help untangle issues of bidirectionality and aid in determining the direction of causality between PTSD and inflammation. Last, we conclude with future research directions and consider potential implications for interventions or treatment approaches based on this growing body of literature.
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Affiliation(s)
- Jennifer A. Sumner
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA,Correspondence to: Jennifer A. Sumner, University of California, Los Angeles, Department of Psychology, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095. Telephone: 1 (310) 794-9860;
| | - Kristen M. Nishimi
- Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Karestan C. Koenen
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Andrea L. Roberts
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Laura D. Kubzansky
- Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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39
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Biener AI, Cawley J, Meyerhoefer C. The medical care costs of obesity and severe obesity in youth: An instrumental variables approach. HEALTH ECONOMICS 2020; 29:624-639. [PMID: 32090412 DOI: 10.1002/hec.4007] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
This paper is the first to use the method of instrumental variables to estimate the impact of obesity and severe obesity in youth. on U.S. medical care costs. We examine data from the Medical Expenditure Panel Survey for 2001-2015 and instrument for child BMI using the BMI of the child's biological mother. Instrumental variables estimates indicate that obesity in youth raises annual medical care costs by $907 (in 2015 dollars) or 92%, which is considerably higher than previous estimates of the association of youth obesity with medical costs. We find that obesity in youth significantly raises costs in all major categories of medical care: outpatient doctor visits, inpatient hospital stays, and prescription drugs. The costs of youth obesity are borne almost entirely by third-party payers, which is consistent with substantial externalities of youth obesity, which in turn represents an economic rationale for government intervention.
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Affiliation(s)
- Adam I Biener
- Department of Economics, Lafayette College, Easton, Pennsylvania, USA
| | - John Cawley
- Department of Policy Analysis and Management and Department of Economics, Cornell University, New York, USA
| | - Chad Meyerhoefer
- College of Business and Economics, Lehigh University, Bethlehem, Pennsylvania, USA
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40
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Wang J, Chen Q, Chen G, Li Y, Kong G, Zhu C. What is creating the height premium? New evidence from a Mendelian randomization analysis in China. PLoS One 2020; 15:e0230555. [PMID: 32275720 PMCID: PMC7147798 DOI: 10.1371/journal.pone.0230555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/02/2020] [Indexed: 12/18/2022] Open
Abstract
This study uses a Mendelian randomization approach to resolve the difficulties of identifying the causal relationship between height and earnings by using a unique sample of 3,427 respondents from mainland China with sociodemographic information linked to individual genotyping data. Exploiting genetic variations to create instrumental variables for observed height, we find that while OLS regressions yield that an additional centimeter in height is associated with a 10–13% increase in one’s annual earnings, IV estimates reveal only an insubstantial causal effect of height. Further analyses suggest that the observed height premium is likely to pick up the impacts of several cognitive/noncognitive skills on earnings confounded in previous studies, such as mental health, risk preference, and personality factors. Our study is the first empirical study that employs genetic IVs in developing countries, and our results contribute to the recent debate on the mechanism of height premium.
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Affiliation(s)
- Jun Wang
- School of Public Administration and Policy, Renmin University of China, Beijing, China
- Center for Health Policy Research and Evaluation, Renmin University of China, Beijing, China
| | - Qihui Chen
- College of Economics and Management, China Agricultural University, Beijing, China
| | | | | | - Guoshu Kong
- School of Public Administration and Policy, Renmin University of China, Beijing, China
- Center for Health Policy Research and Evaluation, Renmin University of China, Beijing, China
| | - Chen Zhu
- College of Economics and Management, China Agricultural University, Beijing, China
- * E-mail:
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41
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Kari JT, Viinikainen J, Böckerman P, Tammelin TH, Pitkänen N, Lehtimäki T, Pahkala K, Hirvensalo M, Raitakari OT, Pehkonen J. Education leads to a more physically active lifestyle: Evidence based on Mendelian randomization. Scand J Med Sci Sports 2020; 30:1194-1204. [PMID: 32176397 DOI: 10.1111/sms.13653] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/14/2020] [Accepted: 03/05/2020] [Indexed: 12/14/2022]
Abstract
Physical inactivity is a major health risk worldwide. Observational studies suggest that higher education is positively related to physical activity, but it is not clear whether this relationship constitutes a causal effect. Using participants (N = 1651) drawn from the Cardiovascular Risk in Young Finns Study linked to nationwide administrative data from Statistics Finland, this study examined whether educational attainment, measured by years of education, is related to adulthood physical activity in terms of overall physical activity, weekly hours of intensive activity, total steps per day, and aerobic steps per day. We employed ordinary least squares (OLS) models and extended the analysis using an instrumental variables approach (Mendelian randomization, MR) with a genetic risk score as an instrument for years of education. Based on the MR results, it was found that years of education is positively related to physical activity. On average, one additional year of education leads to a 0.62-unit higher overall physical activity (P < .01), 0.26 more hours of weekly intensive activity (P < .05), 560 more steps per day (P < .10), and 390 more aerobic steps per day (P < .09). The findings indicate that education may be a factor leading to higher leisure-time physical activity and thus promoting global health.
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Affiliation(s)
- Jaana T Kari
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Jutta Viinikainen
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
| | - Petri Böckerman
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland.,Labour Institute for Economic Research, Helsinki, Finland.,IZA Institute of Labor Economics, Bonn, Germany
| | - Tuija H Tammelin
- LIKES Research Centre for Physical Activity and Health, Jyväskylä, Finland
| | - Niina Pitkänen
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland.,Centre for Population Health Research, Turku University Hospital, University of Turku, Turku, Finland
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories and Faculty of Medicine and Health Technology, Finnish Cardiovascular Research Center - Tampere, Tampere University, Tampere, Finland
| | - Katja Pahkala
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland.,Centre for Population Health Research, Turku University Hospital, University of Turku, Turku, Finland.,Paavo Nurmi Centre, Sports & Exercise Medicine Unit, Department of Physical Activity and Health, Turku, Finland
| | - Mirja Hirvensalo
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Olli T Raitakari
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland.,Centre for Population Health Research, Turku University Hospital, University of Turku, Turku, Finland.,Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland
| | - Jaakko Pehkonen
- Jyväskylä University School of Business and Economics, University of Jyväskylä, Jyväskylä, Finland
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42
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Kurz CF, Laxy M. Application of Mendelian Randomization to Investigate the Association of Body Mass Index with Health Care Costs. Med Decis Making 2020; 40:156-169. [DOI: 10.1177/0272989x20905809] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Causal effect estimates for the association of obesity with health care costs can be biased by reversed causation and omitted variables. In this study, we use genetic variants as instrumental variables to overcome these limitations, a method that is often called Mendelian randomization (MR). We describe the assumptions, available methods, and potential pitfalls of using genetic information and how to address them. We estimate the effect of body mass index (BMI) on total health care costs using data from a German observational study and from published large-scale data. In a meta-analysis of several MR approaches, we find that models using genetic instruments identify additional annual costs of €280 for a 1-unit increase in BMI. This is more than 3 times higher than estimates from linear regression without instrumental variables (€75). We found little evidence of a nonlinear relationship between BMI and health care costs. Our results suggest that the use of genetic instruments can be a powerful tool for estimating causal effects in health economic evaluation that might be superior to other types of instruments where there is a strong association with a modifiable risk factor.
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Affiliation(s)
- Christoph F. Kurz
- Institute of Health Economics and Health Care Management, Helmholtz Zentrum München, Neuherberg, Bayern, Germany
- German Center for Diabetes Research, Neuherberg, Bayern, Germany
| | - Michael Laxy
- Institute of Health Economics and Health Care Management, Helmholtz Zentrum München, Neuherberg, Bayern, Germany
- German Center for Diabetes Research, Neuherberg, Bayern, Germany
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43
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Dixon P, Hollingworth W, Harrison S, Davies NM, Davey Smith G. Mendelian Randomization analysis of the causal effect of adiposity on hospital costs. JOURNAL OF HEALTH ECONOMICS 2020; 70:102300. [PMID: 32014825 PMCID: PMC7188219 DOI: 10.1016/j.jhealeco.2020.102300] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 01/06/2020] [Accepted: 01/14/2020] [Indexed: 05/12/2023]
Abstract
Estimates of the marginal effect of measures of adiposity such as body mass index (BMI) on healthcare costs are important for the formulation and evaluation of policies targeting adverse weight profiles. Most estimates of this association are affected by endogeneity bias. We use a novel identification strategy exploiting Mendelian Randomization - random germline genetic variation modelled using instrumental variables - to identify the causal effect of BMI on inpatient hospital costs. Using data on over 300,000 individuals, the effect size per person per marginal unit of BMI per year varied according to specification, including £21.22 (95% confidence interval (CI): £14.35-£28.07) for conventional inverse variance weighted models to £18.85 (95% CI: £9.05-£28.65) for penalized weighted median models. Effect sizes from Mendelian Randomization models were larger in most cases than non-instrumental variable multivariable adjusted estimates (£13.47, 95% CI: £12.51-£14.43). There was little evidence of non-linearity. Within-family estimates, intended to address dynastic biases, were imprecise.
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Affiliation(s)
- Padraig Dixon
- Population Health Sciences, University of Bristol, United Kingdom; MRC Integrative Epidemiology Unit, University of Bristol, United Kingdom.
| | | | - Sean Harrison
- Population Health Sciences, University of Bristol, United Kingdom; MRC Integrative Epidemiology Unit, University of Bristol, United Kingdom
| | - Neil M Davies
- Population Health Sciences, University of Bristol, United Kingdom; MRC Integrative Epidemiology Unit, University of Bristol, United Kingdom
| | - George Davey Smith
- Population Health Sciences, University of Bristol, United Kingdom; MRC Integrative Epidemiology Unit, University of Bristol, United Kingdom; NIHR Biomedical Research Centre, University of Bristol, United Kingdom
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44
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Spiller W, Jung KJ, Lee JY, Jee SH. Precision Medicine and Cardiovascular Health: Insights from Mendelian Randomization Analyses. Korean Circ J 2019; 50:91-111. [PMID: 31845553 PMCID: PMC6974657 DOI: 10.4070/kcj.2019.0293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 11/11/2022] Open
Abstract
Cardiovascular disease (CVD) is considered a primary driver of global mortality and is estimated to be responsible for approximately 17.9 million deaths annually. Consequently, a substantial body of research related to CVD has developed, with an emphasis on identifying strategies for the prevention and effective treatment of CVD. In this review, we critically examine the existing CVD literature, and specifically highlight the contribution of Mendelian randomization analyses in CVD research. Throughout this review, we assess the extent to which research findings agree across a range of studies of differing design within a triangulation framework. If differing study designs are subject to non-overlapping sources of bias, consistent findings limit the extent to which results are merely an artefact of study design. Consequently, broad agreement across differing studies can be viewed as providing more robust causal evidence in contrast to limiting the scope of the review to a single specific study design. Utilising the triangulation approach, we highlight emerging patterns in research findings, and explore the potential of identified risk factors as targets for precision medicine and novel interventions.
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Affiliation(s)
- Wes Spiller
- Department of Population Health Sciences, University of Bristol, Bristol, UK
| | - Keum Ji Jung
- Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea
| | - Ji Young Lee
- Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea
| | - Sun Ha Jee
- Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea.
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45
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Reporting and guidelines for mendelian randomization analysis: A systematic review of oncological studies. Cancer Epidemiol 2019; 62:101577. [PMID: 31377572 DOI: 10.1016/j.canep.2019.101577] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/16/2019] [Accepted: 07/22/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND Mendelian randomization (MR) analyses have been increasingly used to seek evidence of causal associations. This systematic review aims at characterizing and evaluating the reporting of MR analyses in oncological studies. METHODS The PubMed database was searched to identify MR cancer studies until December 31, 2017. Two of the authors independently selected and evaluated reporting quality of the studies. Reporting quality in MR studies before 2016 and in 2016/17 was compared. RESULTS Cancer studies with MR analyses in 2016 and 2017 accounted for 55.8% of the total number of studies identified. In the 77 eligible articles, 39 (50.6%) did not report subjects' characteristics, 53 (68.8%) did not conduct power estimation, 40 (51.9%) did not state all of the first three MR assumptions (i.e., genetic instrument is associated with exposure, is not associated with confounders, and acts on outcome only through exposure), and 31 (40.3%) did not exclude SNPs that diverged from Hardy-Weinberg equilibrium. More studies estimated power in 2016/2017 than before 2016 (p = 0.028). CONCLUSIONS Some MR cancer studies did not sufficiently report essential information, posing obstacles for critical appraisal. This study proposes for MR analysis a guideline/checklist for future publications in cancer and other biomedical research.
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46
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Fu R, Noguchi H, Kaneko S, Kawamura A, Kang C, Takahashi H, Tamiya N. How do cardiovascular diseases harm labor force participation? Evidence of nationally representative survey data from Japan, a super-aged society. PLoS One 2019; 14:e0219149. [PMID: 31276516 PMCID: PMC6611572 DOI: 10.1371/journal.pone.0219149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/17/2019] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To evaluate how cardiovascular diseases harm labor force participation (LFP) among the Japanese population and verify the validity of plasma biomarkers as instrumental variables of cardiovascular diseases after adjusting for a broad set of confounders including dietary intake. DESIGN Using nationally representative repeated cross-sectional surveys in Japan, the Comprehensive Survey of Living Conditions and National Health and Nutrition Survey, with plasma biomarkers as instrumental variables for quasi-randomization. SETTING Onset of cardiovascular diseases in those receiving regular treatment for hypertension, intracerebral hemorrhage, intracerebral infarction, angina pectoris, myocardial infarction, or other types of cardiovascular diseases. PARTICIPANTS A total of 65,615 persons aged ≥ 20 years (35,037 women and 30,578 men) who completed a survey conducted every three years from 1995 through 2013. MAIN OUTCOME MEASURES Respondent employment and weekly working hours during each survey year. RESULTS Cardiovascular diseases significantly and remarkably reduced the probability of working by 15.4% (95% CI: -30.6% to -0.2%). The reduction in working probability was detected for women only. Respondents aged ≥ 40 years were less likely to work once diagnosed and the reduction was enlarged for those aged ≥ 65 years, while those aged < 40 years appeared to be unaffected. Probability of engaging in manual labor significantly decreased once diagnosed; however, no impact was found for cognitive occupations. Among employed respondents, the adverse effects of cardiovascular diseases decreased working hours by five hours per week. Validity of the biomarker instrumental variables was generally verified. CONCLUSIONS A vicious circle is suggested between LFP and unfavorable health. However, the effects vary across age, sex, and occupation type, even after adjusting for causal effects, which could cause a downward bias in LFP impact. ATTRIBUTES cardiovascular disease, labor force participation, instrumental variable method as quasi-randomization, plasma biomarker, Comprehensive Survey of Living Conditions, National Health and Nutrition Survey.
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Affiliation(s)
- Rong Fu
- Waseda University, Faculty of Political Science and Economics, Tokyo, Japan
| | - Haruko Noguchi
- Waseda University, Faculty of Political Science and Economics, Tokyo, Japan
| | - Shuhei Kaneko
- Waseda University, Faculty of Political Science and Economics, Tokyo, Japan
| | - Akira Kawamura
- Waseda University, Faculty of Political Science and Economics, Tokyo, Japan
| | - Cheolmin Kang
- Waseda University, Faculty of Political Science and Economics, Tokyo, Japan
| | | | - Nanako Tamiya
- Health Services Research & Development Center, University of Tsukuba, Tsukuba, Japan
- Department of Health Services Research, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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47
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Epidemiology, genetic epidemiology and Mendelian randomisation: more need than ever to attend to detail. Hum Genet 2019; 139:121-136. [PMID: 31134333 PMCID: PMC6942032 DOI: 10.1007/s00439-019-02027-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 05/09/2019] [Indexed: 12/02/2022]
Abstract
In the current era, with increasing availability of results from genetic association studies, finding genetic instruments for inferring causality in observational epidemiology has become apparently simple. Mendelian randomisation (MR) analyses are hence growing in popularity and, in particular, methods that can incorporate multiple instruments are being rapidly developed for these applications. Such analyses have enormous potential, but they all rely on strong, different, and inherently untestable assumptions. These have to be clearly stated and carefully justified for every application in order to avoid conclusions that cannot be replicated. In this article, we review the instrumental variable assumptions and discuss the popular linear additive structural model. We advocate the use of tests for the null hypothesis of ‘no causal effect’ and calculation of the bounds for a causal effect, whenever possible, as these do not rely on parametric modelling assumptions. We clarify the difference between a randomised trial and an MR study and we comment on the importance of validating instruments, especially when considering them for joint use in an analysis. We urge researchers to stand by their convictions, if satisfied that the relevant assumptions hold, and to interpret their results causally since that is the only reason for performing an MR analysis in the first place.
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48
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van Kippersluis H, Rietveld CA. Pleiotropy-robust Mendelian randomization. Int J Epidemiol 2019; 47:1279-1288. [PMID: 28338774 DOI: 10.1093/ije/dyx002] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2017] [Indexed: 01/15/2023] Open
Abstract
Background The potential of Mendelian randomization studies is rapidly expanding due to: (i) the growing power of genome-wide association study (GWAS) meta-analyses to detect genetic variants associated with several exposures; and (ii) the increasing availability of these genetic variants in large-scale surveys. However, without a proper biological understanding of the pleiotropic working of genetic variants, a fundamental assumption of Mendelian randomization (the exclusion restriction) can always be contested. Methods We build upon and synthesize recent advances in the literature on instrumental variables (IVs) estimation that test and relax the exclusion restriction. Our pleiotropy-robust Mendelian randomization (PRMR) method first estimates the degree of pleiotropy, and in turn corrects for it. If (i) a subsample exists for which the genetic variants do not affect the exposure; (ii) the selection into this subsample is not a joint consequence of the IV and the outcome; (iii) pleiotropic effects are homogeneous, PRMR obtains unbiased estimates of causal effects. Results Simulations show that existing MR methods produce biased estimators for realistic forms of pleiotropy. Under the aforementioned assumptions, PRMR produces unbiased estimators. We illustrate the practical use of PRMR by estimating the causal effect of: (i) tobacco exposure on body mass index (BMI); (ii) prostate cancer on self-reported health; and (iii) educational attainment on BMI in the UK Biobank data. Conclusions PRMR allows for instrumental variables that violate the exclusion restriction due to pleiotropy, and it corrects for pleiotropy in the estimation of the causal effect. If the degree of pleiotropy is unknown, PRMR can still be used as a sensitivity analysis.
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Affiliation(s)
- Hans van Kippersluis
- Erasmus School of Economics, Erasmus University Rotterdam, The Netherlands.,Department of Economics, Chinese University of Hong Kong, Hong Kong SAR.,Tinbergen Institute, Amsterdam, The Netherlands
| | - Cornelius A Rietveld
- Erasmus School of Economics, Erasmus University Rotterdam, The Netherlands.,Tinbergen Institute, Amsterdam, The Netherlands.,Erasmus University Rotterdam Institute for Behavior and Biology, Erasmus University Rotterdam, The Netherlands
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49
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Pehkonen J, Viinikainen J, Böckerman P, Pitkänen N, Lehtimäki T, Raitakari O. Health endowment and later-life outcomes in the labour market: Evidence using genetic risk scores and reduced-form models. SSM Popul Health 2019; 7:100379. [PMID: 30906844 PMCID: PMC6411586 DOI: 10.1016/j.ssmph.2019.100379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 02/14/2019] [Accepted: 02/17/2019] [Indexed: 10/28/2022] Open
Abstract
This paper examines the relationship between health endowment and later-life outcomes in the labour market. The analysis is based on reduced-form models in which labour market outcomes are regressed on genetic variants related to the increased risk of cardiovascular diseases. We use linked Finnish data that have many strengths. Genetic risk scores constitute exogenous measures for health endowment, and accurate administrative tax records on earnings, employment and social income transfers provide a comprehensive account of an individual's long-term performance in the labour market. The results show that although the direction of an effect is generally consistent with theoretical reasoning, the effects of health endowment on outcomes are statistically weak, and the hypothesis of no effect can be rejected only in one case: genetic endowment related to obesity influences male earnings and employment in prime age. Due to the sample size (N = 1651), the results should be interpreted with caution and should be confirmed in larger samples and in other institutional settings.
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Affiliation(s)
- Jaakko Pehkonen
- University of Jyväskylä, School of Business and Economics, Jyväskylä, Finland
| | - Jutta Viinikainen
- University of Jyväskylä, School of Business and Economics, Jyväskylä, Finland
| | - Petri Böckerman
- University of Jyväskylä, School of Business and Economics, Jyväskylä, Finland
- Labour Institute for Economic Research, Helsinki, Finland
- IZA, Bonn, Germany
| | - Niina Pitkänen
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories and Finnish Cardiovascular Research Center Tampere, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Olli Raitakari
- Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Turku, Finland
- Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku, Finland
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50
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Gupta V, Sachdeva MP, Walia GK. "Mendelian Randomization" Approach in Economic Assessment of Health Conditions. Front Public Health 2019; 7:2. [PMID: 30778381 PMCID: PMC6369183 DOI: 10.3389/fpubh.2019.00002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/04/2019] [Indexed: 01/30/2023] Open
Abstract
The increased prevalence of non-communicable chronic diseases (NCDs) is reflected in the rising economic burden of health conditions. Observational studies conducted in health economics research are detecting associations of NCDs or related risk factors with economic measures like health insurance, economic inequalities, accessibility of jobs, education, annual income, health expenditure, etc. The inferences of such relationships do not prove causation and are limited to associations which are many times influenced by confounding factors and reverse causation. Mendelian randomization (MR) approach is a useful method for exploring causal relations between modifiable risk factors and measures of health economics. The application of MR in economic assessment of health conditions has been started and is producing fruitful results.
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Affiliation(s)
- Vipin Gupta
- Department of Anthropology, University of Delhi, New Delhi, India
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