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Wu W, Wu G, Wei J, Lawrence WR, Deng X, Zhang Y, Chen S, Wang Y, Lin X, Chen D, Ruan X, Lin Q, Li Z, Lin Z, Hao C, Du Z, Zhang W, Hao Y. Potential causal links and mediation pathway between urban greenness and lung cancer mortality: Result from a large cohort (2009 to 2020). SUSTAINABLE CITIES AND SOCIETY 2024; 101:105079. [PMID: 38222851 PMCID: PMC10783447 DOI: 10.1016/j.scs.2023.105079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Urban greenness, as a vital component of the urban environment, plays a critical role in mitigating the adverse effects of rapid urbanization and supporting urban sustainability. However, the causal links between urban greenness and lung cancer mortality and its potential causal pathway remain poorly understood. Based on a prospective community-based cohort with 581,785 adult participants in southern China, we applied a doubly robust Cox proportional hazard model to estimate the causal associations between urban greenness exposure and lung cancer mortality. A general multiple mediation analysis method was utilized to further assess the potential mediating roles of various factors including particulate matter (PM1, PM2.5-1, and PM10-2.5), temperature, physical activity, and body mass index (BMI). We observed that each interquartile range (IQR: 0.06) increment in greenness exposure was inversely associated with lung cancer mortality, with a hazard ratio (HR) of 0.89 (95 % CI: 0.83, 0.96). The relationship between greenness and lung cancer mortality might be partially mediated by particulate matter, temperature, and physical activity, yielding a total indirect effect of 0.826 (95 % CI: 0.769, 0.887) for each IQR increase in greenness exposure. Notably, the protective effect of greenness against lung cancer mortality could be achieved primarily by reducing the particulate matter concentration.
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Affiliation(s)
- Wenjing Wu
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Gonghua Wu
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Jing Wei
- Department of Atmospheric and Oceanic Science, Earth System Science Interdisciplinary Center, University of Maryland, College Park, USA
| | - Wayne R Lawrence
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA
| | - Xinlei Deng
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, USA
| | - Yuqin Zhang
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Shirui Chen
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Ying Wang
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Xiao Lin
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Dan Chen
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Xinling Ruan
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Qiaoxuan Lin
- Department of Statistics, Guangzhou Health Technology Identification & Human Resources Assessment Center, China
| | - Zhiqiang Li
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Ziqiang Lin
- Department of Preventive Medicine, School of Basic Medicine and Public Health, Jinan University, Guangzhou, China
| | - Chun Hao
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Zhicheng Du
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Wangjian Zhang
- Department of Medical Statistics, School of Public Health & Center for Health Information Research &Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
| | - Yuantao Hao
- Peking University Center for Public Health and Epidemic Preparedness & Response, Peking, China
- Key Laboratory of Epidemiology of Major Diseases, Peking University, Ministry of Education, China
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Didelot X, Franceschi V, Frost SDW, Dennis A, Volz EM. Model design for nonparametric phylodynamic inference and applications to pathogen surveillance. Virus Evol 2023; 9:vead028. [PMID: 37229349 PMCID: PMC10205094 DOI: 10.1093/ve/vead028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 04/17/2023] [Accepted: 04/26/2023] [Indexed: 05/27/2023] Open
Abstract
Inference of effective population size from genomic data can provide unique information about demographic history and, when applied to pathogen genetic data, can also provide insights into epidemiological dynamics. The combination of nonparametric models for population dynamics with molecular clock models which relate genetic data to time has enabled phylodynamic inference based on large sets of time-stamped genetic sequence data. The methodology for nonparametric inference of effective population size is well-developed in the Bayesian setting, but here we develop a frequentist approach based on nonparametric latent process models of population size dynamics. We appeal to statistical principles based on out-of-sample prediction accuracy in order to optimize parameters that control shape and smoothness of the population size over time. Our methodology is implemented in a new R package entitled mlesky. We demonstrate the flexibility and speed of this approach in a series of simulation experiments and apply the methodology to a dataset of HIV-1 in the USA. We also estimate the impact of non-pharmaceutical interventions for COVID-19 in England using thousands of SARS-CoV-2 sequences. By incorporating a measure of the strength of these interventions over time within the phylodynamic model, we estimate the impact of the first national lockdown in the UK on the epidemic reproduction number.
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Affiliation(s)
- Xavier Didelot
- School of Life Sciences and Department of Statistics, University of Warwick, United Kingdom
| | - Vinicius Franceschi
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, United Kingdom
| | | | - Ann Dennis
- Department of Medicine, University of North Carolina, USA
| | - Erik M Volz
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, United Kingdom
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Chen Z, Du J, Song Q, Yang J, Wu Y. A prediction model of cognitive impairment risk in elderly illiterate Chinese women. Front Aging Neurosci 2023; 15:1148071. [PMID: 37181625 PMCID: PMC10169753 DOI: 10.3389/fnagi.2023.1148071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Objective To establish and validate a targeted model for the prediction of cognitive impairment in elderly illiterate Chinese women. Methods 1864 participants in the 2011-2014 cohort and 1,060 participants in the 2014-2018 cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were included in this study. The Chinese version of the Mini-Mental State Examination (MMSE) was used to measure cognitive function. Demographics and lifestyle information were collected to construct a risk prediction model by a restricted cubic spline Cox regression. The discrimination and accuracy of the model were assessed by the area under the curve (AUC) and the concordance index, respectively. Results A total of seven critical variables were included in the final prediction model for cognitive impairment risk, including age, MMSE score, waist-to-height ratio (WHtR), psychological score, activities of daily living (ADL), instrumental abilities of daily living (IADL), and frequency of tooth brushing. The internal and external validation AUCs were 0.8 and 0.74, respectively; and the receiver operating characteristic (ROC) curves indicated good performance ability of the constructed model. Conclusion A feasible model to explore the factors influencing cognitive impairment in elderly illiterate women in China and to identify the elders at high risk was successfully constructed.
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Affiliation(s)
- Zhaojing Chen
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Jiaolan Du
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Qin Song
- Department of Occupational and Environmental Health, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Jun Yang
- Department of Nutrition and Toxicology, School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yinyin Wu
- Department of Epidemiology and Health Statistics, School of Public Health, Hangzhou Normal University, Hangzhou, China
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Li S, Wei J, Hu Y, Liu Y, Hu M, Shi Y, Xue Y, Liu M, Xie W, Guo X, Liu X. Long-term effect of intermediate particulate matter (PM 1-2.5) on incident asthma among middle-aged and elderly adults: A national population-based longitudinal study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160204. [PMID: 36403826 DOI: 10.1016/j.scitotenv.2022.160204] [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: 06/19/2022] [Revised: 10/25/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND There is insufficient evidence about the long-term effects of intermediate particulate matter (PM1-2.5) on asthma development in adults aged 45 years and above. This study aimed to investigate the relationship between long-term exposure to PM1-2.5 and the incidence of asthma in adults aged 45 years and above. METHODS A cohort study based on the China Health and Retirement Longitudinal Study (CHARLS) database was conducted to investigate the long-term effects of PM1-2.5 on self-reported asthma incidence in adults aged 45 years and above in China from 2011 to 2018. The PM concentrations were estimated using a high-resolution (1 km2) satellite-based spatiotemporal model. A covariate-adjusted generalized linear mixed model was used to analyze the relationship between long-term exposure to PM1-2.5 and the incidence of asthma. Effect modifications and sensitivity analysis were conducted. RESULTS After a 7-year follow-up, 103 (1.61 %) of the 6400 participants developed asthma. Each 10 μg/m3 increment in the 1-, 2-, 3-, and 4-year moving average concentrations of PM1-2.5 corresponded to a 1.82 [95 % confidence interval (CI):1.11-2.98], 1.95 (95 % CI: 1.24-3.07), 1.95 (95 % CI: 1.26-3.03) and 1.88 (95 % CI: 1.26-2.81) fold risk for incident asthma, respectively. A significant multiplicative interaction was observed between socioeconomic level and long-term exposure to PM1-2.5. Stratified analysis showed that smokers and those with lower socioeconomic levels were at higher risk of incident asthma related to PM1-2.5. Restricted cubic splines showed an increasing trend in asthma incidence with increasing PM1-2.5. Sensitivity analyses showed that our model was robust. CONCLUSION Long-term exposure to PM1-2.5 was positively associated with incident asthma in middle-aged and elderly individuals. Participants with a history of smoking and lower socioeconomic levels had a higher risk. More studies are warranted warrant to establish an accurate reference value of PM1-2.5 to mitigate the growing asthma burden.
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Affiliation(s)
- Shuting Li
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
| | - Jing Wei
- Department of Chemical and Biochemical Engineering, Iowa Technology Institute, Center for Global and Regional Environmental Research, University of Iowa, USA
| | - Yaoyu Hu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China
| | - Yuhong Liu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China
| | - Meiling Hu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
| | - Yadi Shi
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China
| | - Yongxi Xue
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
| | - Mengmeng Liu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
| | - Wenhan Xie
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China
| | - Xiuhua Guo
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China; National Institute for Data Science in Health and Medicine, Capital Medical University, China; Centre for Precision Health, School of Medical and Health Sciences, Edith Cowan University, Australia.
| | - Xiangtong Liu
- School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
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Association between Changes in Protein Intake and Risk of Cognitive Impairment: A Prospective Cohort Study. Nutrients 2022; 15:nu15010002. [PMID: 36615661 PMCID: PMC9824869 DOI: 10.3390/nu15010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/11/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Little is known about the role of change in protein intake in affecting cognitive function among older adults. Therefore, we aimed to investigate the associations between the change in protein intake from various food groups and cognitive impairment among older adults in a prospective cohort study. A total of 6951 participants without cognitive impairment or dementia were included in this study. The frequency of protein intake from various food groups was measured by a food frequency questionnaire at baseline and follow-up. Multivariable Cox hazard models with time as the underlying time metric applied to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). During the 37,535 person-years of follow-up, 1202 (17.3%) participants developed cognitive impairment. The improvement in overall protein intake was negatively associated with cognitive impairment with multivariable-adjusted HR of 0.98 (95% CI = 0.97-0.99). Compared with participants with stable change, those with an extreme decline in animal-based protein intake had a 48% higher risk of cognitive impairment. The associations of changes in protein from six food groups with cognitive impairment were in a similar direction to the main result. Protective associations between improving protein intake and a reduced risk of cognitive impairment were observed.
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Xu XY, Wang SS, Niu L, Leung ISH, Tian QB. Association of leisure activity changes and reversion from mild cognitive impairment to normal cognitive function among older adults: A prospective cohort study. Front Public Health 2022; 10:1035762. [PMID: 36483237 PMCID: PMC9724021 DOI: 10.3389/fpubh.2022.1035762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022] Open
Abstract
Background Older adults with mild cognitive impairment (MCI) have the possibility of reverting to normal cognitive function. Leisure activity engagement (LAE) plays a critical role in the progress of the cognitive function. A better understanding of the dynamic relationship between LAE and MCI reversion would inform the implementation of preclinical dementia interventions. This study aimed to investigate the association between change patterns of LAE and MCI reversion among older adults using the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database. Study design Longitudinal population-based study. Methods Older adults with MCI at the baseline were enrolled in this study. Information about cognitive function, overall, cognitively stimulating, physically active/demanding, and socially engaged LAE was collected at baseline and follow-up. Adjusted hazard ratios (HRs) for reversion and 95% confidence intervals (CIs) were calculated by Cox hazard models with time as the underlying time metric. We also assessed potential effect modifications by creating a cross-product of the stratifying variable with LAE change patterns in the fully adjusted model. Results The restricted cubic spline showed that the association between LAE change scores and MCI reversion rate was statistically significant and nonlinear (p<0.01). Taking participants in the low-low group as a reference, participants in the low-medium, low-high, medium-medium, medium-high, high-medium, and high-high groups had increased possibilities of MCI reversion with HRs (95% CI) of 2.19 (1.57-3.06), 2.97 (2.13-4.13), 0.87 (0.64-1.19), 2.28 (1.71-3.03), 2.78 (2.10-3.69), 1.93 (1.43-2.59), and 2.74 (2.09-3.60), respectively. Further stratified models showed that the impact of LAE change patterns on MCI reversion varied in different ages (nonagenarian, octogenarian, and younger elderly) and gender. Conclusions Participants who maintained the highest LAE had the greatest possibility of MCI reversion. Meanwhile, a higher level of LAE maintenance was associated with the increased possibility of MCI reversion. These results provide a practical message to older adults about how dynamic changes in LAE are associated with improved cognitive function.
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Affiliation(s)
- Xin Yi Xu
- Postdoctoral Research Station in Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Shan Shan Wang
- School of Nursing, Centre for Gerontological Nursing, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China,School of Nursing and Health, Zhengzhou University, Zhengzhou, China
| | - Li Niu
- International Education College, Hebei Medical University, Shijiazhuang, China
| | - Isaac Sze Him Leung
- Department of Statistics, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Qing Bao Tian
- Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, Shijiazhuang, China,*Correspondence: Qing Bao Tian
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Song Y, Zeng L, Gao J, Chen L, Sun C, Yan M, Li M, Jiang H. Adherence to High Dietary Diversity and Incident Cognitive Impairment for the Oldest-Old: A Community-Based, Nationwide Cohort Study. Nutrients 2022; 14:4530. [PMID: 36364792 PMCID: PMC9655345 DOI: 10.3390/nu14214530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/22/2022] [Accepted: 10/25/2022] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND AND AIMS Dietary diversity change is associated with cognitive function, however, whether the effect still exists among the oldest-old (80+) is unclear. Our aim was to examine the effect of dietary diversity changes on cognitive impairment for the oldest-old in a large prospective cohort. METHODS Within the Chinese Longitudinal Healthy Longevity Study, 6237 adults older than 80 years were included. The dietary diversity score (DDS) was assessed by a simplified food frequency questionnaire (FFQ). Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score lower than 18 points. Cognitive decline was defined as a reduction of total MMSE score ≥3 points, and cognitive decline of different subdomains was defined as a reduction of ≥15% in the corresponding cognitive domain. The multivariate-adjusted Cox proportional hazard model evaluated the effects of DDS change on cognitive decline. The linear mixed-effect model was used to test subsequent changes in MMSE over the years. RESULTS During 32,813 person-years of follow-up, 1829 participants developed cognitive impairment. Relative to the high-high DDS change pattern, participants in the low-low and high-low patterns were associated with an increased risk of cognitive impairment with a hazard ratio (95% confidential interval, CI) of 1.43 (1.25, 1.63) and 1.44 (1.24, 1.67), and a faster decline in the MMSE score over the follow-up year. Participants with the low-high pattern had a similar incidence of cognitive impairment with HRs (95% CI) of 1.03 (0.88, 1.20). Compared with the stable DDS status group (-1-1), the risk of cognitive impairment was higher for those with large declines in DDS (≤-5) and the HR was 1.70 (95% CI: 1.44, 2.01). CONCLUSIONS Even for people older than 80, dietary diversity change is a simple method to identify those who had a high risk of cognitive decline. Keeping high dietary diversity is beneficial for cognitive function and its subdomain even in the final phase of life, especially for females and the illiterate oldest-old.
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Affiliation(s)
- Yangyang Song
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Lu Zeng
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Julin Gao
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Lei Chen
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Chuanhui Sun
- The First Affiliated Hospital of Xinxiang Medical University, Xinxiang 453100, China
| | - Mengyao Yan
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Mengnan Li
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
| | - Hongli Jiang
- Dialysis Department of Nephrology Hospital, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China
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Wang H, Lambourg E, Guthrie B, Morales DR, Donnan PT, Bell S. Patient outcomes following AKI and AKD: a population-based cohort study. BMC Med 2022; 20:229. [PMID: 35854309 PMCID: PMC9297625 DOI: 10.1186/s12916-022-02428-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/06/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Acute kidney injury (AKI) is common and associated with adverse outcomes as well as important healthcare costs. However, evidence examining the epidemiology of acute kidney disease (AKD)-recently defined as AKI persisting between 7 and 90 days-remains limited. The aims of this study were to establish the rates of early AKI recovery, progression to AKD and non-recovery; examine risk factors associated with non-recovery and investigate the association between recovery timing and adverse outcomes, in a population-based cohort. METHODS All adult residents of Tayside & Fife, Scotland, UK, with at least one episode of community or hospital-managed AKI using KDIGO creatinine-based definition during the period 1 January 2010 to 31 December 2018 were identified. Logistic regression was used to examine factors associated with non-recovery, and Cox modelling was used to establish associations between AKI recovery timing and risks of mortality and development of de novo CKD. RESULTS Over 9 years, 56,906 patients with at least one AKI episode were identified with 18,773 (33%) of these progressing to AKD. Of those progressing to AKD, 5059 (27%) had still not recovered at day 90 post AKI diagnosis. Risk factors for AKD included: increasing AKI severity, pre-existing cancer or chronic heart failure and recent use of loop diuretics. Compared with early AKI recovery, progression to AKD was associated with increased hazard of 1-year mortality and de novo CKD (HR = 1.20, 95% CI 1.13 to 1.26 and HR = 2.21, 95% CI 1.91 to 2.57 respectively). CONCLUSIONS These findings highlight the importance of early AKI recognition and management to avoid progression to AKD and long-term adverse outcomes.
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Affiliation(s)
- Huan Wang
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, DD1 9SY, UK
| | - Emilie Lambourg
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, DD1 9SY, UK
| | - Bruce Guthrie
- Advanced Care Research Centre, Usher Institute of Population Health Sciences and Informatics, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Daniel R Morales
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, DD1 9SY, UK.,Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Peter T Donnan
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, DD1 9SY, UK
| | - Samira Bell
- Division of Population Health and Genomics, School of Medicine, University of Dundee, Dundee, DD1 9SY, UK. .,Renal Unit, Ninewells Hospital, Dundee, UK.
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Kishan AU, Steigler A, Denham JW, Zapatero A, Guerrero A, Joseph D, Maldonado X, Wong JK, Stish BJ, Dess RT, Pilar A, Reddy C, Wedde TB, Lilleby WA, Fiano R, Merrick GS, Stock RG, Demanes DJ, Moran BJ, Tran PT, Martin S, Martinez-Monge R, Krauss DJ, Abu-Isa EI, Pisansky TM, Choo CR, Song DY, Greco S, Deville C, McNutt T, DeWeese TL, Ross AE, Ciezki JP, Tilki D, Karnes RJ, Tosoian JJ, Nickols NG, Bhat P, Shabsovich D, Juarez JE, Jiang T, Ma TM, Xiang M, Philipson R, Chang A, Kupelian PA, Rettig MB, Feng FY, Berlin A, Tward JD, Davis BJ, Reiter RE, Steinberg ML, Elashoff D, Boutros PC, Horwitz EM, Tendulkar RD, Spratt DE, Romero T. Interplay Between Duration of Androgen Deprivation Therapy and External Beam Radiotherapy With or Without a Brachytherapy Boost for Optimal Treatment of High-risk Prostate Cancer: A Patient-Level Data Analysis of 3 Cohorts. JAMA Oncol 2022; 8:e216871. [PMID: 35050303 PMCID: PMC8778608 DOI: 10.1001/jamaoncol.2021.6871] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
IMPORTANCE Radiotherapy combined with androgen deprivation therapy (ADT) is a standard of care for high-risk prostate cancer. However, the interplay between radiotherapy dose and the required minimum duration of ADT is uncertain. OBJECTIVE To determine the specific ADT duration threshold that provides a distant metastasis-free survival (DMFS) benefit in patients with high-risk prostate cancer receiving external beam radiotherapy (EBRT) or EBRT with a brachytherapy boost (EBRT+BT). DESIGN, SETTINGS, AND PARTICIPANTS This was a cohort study of 3 cohorts assembled from a multicenter retrospective study (2000-2013); a post hoc analysis of the Randomized Androgen Deprivation and Radiotherapy 03/04 (RADAR; 2003-2007) randomized clinical trial (RCT); and a cross-trial comparison of the RADAR vs the Deprivación Androgénica y Radio Terapía (Androgen Deprivation and Radiation Therapy; DART) 01/05 RCT (2005-2010). In all, the study analyzed 1827 patients treated with EBRT and 1108 patients treated with EBRT+BT from the retrospective cohort; 181 treated with EBRT and 203 with EBRT+BT from RADAR; and 91 patients treated with EBRT from DART. The study was conducted from October 15, 2020, to July 1, 2021, and the data analyses, from January 5 to June 15, 2021. EXPOSURES High-dose EBRT or EBRT+BT for an ADT duration determined by patient-physician choice (retrospective) or by randomization (RCTs). MAIN OUTCOMES AND MEASURES The primary outcome was DMFS; secondary outcome was overall survival (OS). Natural cubic spline analysis identified minimum thresholds (months). RESULTS This cohort study of 3 studies totaling 3410 men (mean age [SD], 68 [62-74] years; race and ethnicity not collected) with high-risk prostate cancer found a significant interaction between the treatment type (EBRT vs EBRT+BT) and ADT duration (binned to <6, 6 to <18, and ≥18 months). Natural cubic spline analysis identified minimum duration thresholds of 26.3 months (95% CI, 25.4-36.0 months) for EBRT and 12 months (95% CI, 4.9-36.0 months) for EBRT+BT for optimal effect on DMFS. In RADAR, the prolongation of ADT for patients receiving only EBRT was not associated with significant improvements in DMFS (hazard ratio [HR], 1.01; 95% CI, 0.65-1.57); however, for patients receiving EBRT+BT, a longer duration was associated with improved DMFS (DMFS HR, 0.56; 95% CI, 0.36-0.87; P = .01). For patients receiving EBRT alone (DART), 28 months of ADT was associated with improved DMFS compared with 18 months (RADAR HR, 0.37; 95% CI, 0.17-0.80; P = .01). CONCLUSIONS AND RELEVANCE These cohort study findings suggest that the optimal minimum ADT duration for treatment with high-dose EBRT alone is more than 18 months; and for EBRT+BT, it is 18 months or possibly less. Additional studies are needed to determine more precise minimum durations.
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Affiliation(s)
- Amar U. Kishan
- Department of Radiation Oncology, University of California, Los Angeles,Department of Urology, University of California, Los Angeles
| | - Alison Steigler
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - James W. Denham
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | | | | | - David Joseph
- Sir Charles Gairdner Hospital, Perth, West Australia, Australia,Department of Medicine and Surgery, University of Western Australia, Perth, West Australia, Australia
| | | | - Jessica K. Wong
- Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Bradley J. Stish
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Robert T. Dess
- Department of Radiation Oncology, University of Michigan, Ann Arbor
| | - Avinash Pilar
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Chandana Reddy
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | | | | | - Ryan Fiano
- Schiffler Cancer Center, Wheeling Hospital, Wheeling Jesuit University, Wheeling, West Virginia
| | - Gregory S. Merrick
- Schiffler Cancer Center, Wheeling Hospital, Wheeling Jesuit University, Wheeling, West Virginia
| | - Richard G. Stock
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - D. Jeffrey Demanes
- Department of Radiation Oncology, University of California, Los Angeles,California Endocurietherapy Cancer Center, Oakland
| | | | - Phuoc T. Tran
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Santiago Martin
- Department of Radiation Oncology, Program in Solid Tumors, Clínica Universidad de Navarra, Pamplona, Spain
| | - Rafael Martinez-Monge
- Department of Radiation Oncology, Program in Solid Tumors, Clínica Universidad de Navarra, Pamplona, Spain
| | - Daniel J. Krauss
- William Beaumont School of Medicine, Oakland University, Royal Oak, Michigan
| | - Eyad I. Abu-Isa
- Department of Radiation Oncology, University of Michigan, Ann Arbor
| | | | - C. Richard Choo
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Daniel Y. Song
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Stephen Greco
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Curtiland Deville
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Todd McNutt
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Theodore L. DeWeese
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ashley E. Ross
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Jay P. Ciezki
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Derya Tilki
- Department of Urology, University Hospital Hamburg-Eppendorf, Hamburg, Germany,Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | | | - Jeffrey J. Tosoian
- Department of Urology, The James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Nicholas G. Nickols
- Department of Radiation Oncology, University of California, Los Angeles,Department of Radiation Oncology, West Los Angeles Veterans Health Administration, Los Angeles, California
| | - Prashant Bhat
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - David Shabsovich
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Jesus E. Juarez
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Tommy Jiang
- Department of Radiation Oncology, University of California, Los Angeles
| | - T. Martin Ma
- Department of Radiation Oncology, University of California, Los Angeles
| | - Michael Xiang
- Department of Radiation Oncology, University of California, Los Angeles
| | - Rebecca Philipson
- Department of Radiation Oncology, University of California, Los Angeles
| | - Albert Chang
- Department of Radiation Oncology, University of California, Los Angeles
| | | | - Matthew B. Rettig
- Division of Medical Oncology, Ronald Reagan UCLA Medical Center, University of California, Los Angeles,Department of Medical Oncology, West Los Angeles Veterans Health Administration, Los Angeles, California
| | - Felix Y. Feng
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco
| | - Alejandro Berlin
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Jonathan D. Tward
- Department of Radiotherapy Oncology, Huntsman Cancer Institute at the University of Utah, Salt Lake City
| | - Brian J. Davis
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | | | | | - David Elashoff
- Division of General Internal Medicine and Health Services Research, University of California, Los Angeles
| | - Paul C. Boutros
- Department of Urology, University of California, Los Angeles,Department of Human Genetics, University of California, Los Angeles
| | - Eric M. Horwitz
- Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Rahul D. Tendulkar
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Daniel E. Spratt
- Seidman Cancer Center, Case Western Reserve University, Cleveland, Ohio
| | - Tahmineh Romero
- Division of General Internal Medicine and Health Services Research, University of California, Los Angeles
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10
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Govindarajulu U, Bedi S. K-means for shared frailty models. BMC Med Res Methodol 2022; 22:11. [PMID: 35021993 PMCID: PMC8753884 DOI: 10.1186/s12874-021-01424-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 10/01/2021] [Indexed: 11/18/2022] Open
Abstract
Background The purpose of this research was to see how the k-means algorithm can be applied to survival analysis with single events per subject for defining groups, which can then be modeled in a shared frailty model to further allow the capturing the unmeasured confounding not already explained by the covariates in the model. Methods For this purpose we developed our own k-means survival grouping algorithm to handle this approach. We compared a regular shared frailty model with a regular grouping variable and a shared frailty model with a k-means grouping variable in simulations as well as analysis on a real dataset. Results We found that in both simulations as well as real data showed that our k-means clustering is no different than the typical frailty clustering even under different situations of varied case rates and censoring. It appeared our k-means algorithm could be a trustworthy mechanism of creating groups from data when no grouping term exists for including in a frailty term in a survival model or comparing to an existing grouping variable available in the current data to use in a frailty model.
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Affiliation(s)
- Usha Govindarajulu
- Center for Biostatistics, Department of Population Health & Policy Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, NY, New York, USA.
| | - Sandeep Bedi
- Center for Biostatistics, Department of Population Health & Policy Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, NY, New York, USA
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11
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The associations of blood pressure parameters with all-cause and cardiovascular mortality in peritoneal dialysis patients: a cohort study in China. J Hypertens 2021; 38:2252-2260. [PMID: 32618891 DOI: 10.1097/hjh.0000000000002526] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND It remains controversial to claim blood pressure (BP) as a leading risk factor for high risk of death in peritoneal dialysis patients, and less is known about the relationship between BP and mortality in Chinese peritoneal dialysis patients. METHODS From Zhejiang Renal Data System in China, we collected data on patients treated and followed up at 98 peritoneal dialysis centres from 2008 to 2016. The associations of BP parameters [SBP, DBP, mean arterial pressure (MAP) and pulse pressure (PP)] with all-cause and cardiovascular mortality were examined. We fitted Cox models for mortality with penalized splines using nonparametric smoothers. Several sensitivity analyses were performed to confirm the robustness of our primary findings. RESULTS A total of 7335 Chinese peritoneal dialysis patients were included. During a median follow-up of 35.8 months, 1281 (17.5%) patients died. SBP, DBP, MAP follow a U-shaped pattern of both all-cause and cardiovascular mortality. PP presents a reverse L-shaped association with all-cause mortality. Either a higher (SBP >141, DBP >85 or MAP >102 mmHg) or lower (SBP <119, DBP <67 or MAP <88 mmHg) BP tends to have a significantly higher all-cause and cardiovascular mortality risk. Higher PP (>60 mmHg) is related to a higher risk of all-cause mortality, but not cardiovascular mortality. These associations remain the same in our competing risk analysis and subgroup analyses. CONCLUSION These data indicate U-shaped associations of SBP, DBP and MAP with all-cause mortality and cardiovascular mortality, respectively, and a reverse L-shaped association of PP with all-cause mortality. Further studies are needed to reliably establish the optimal BP targets for better hypertension control in peritoneal dialysis patients.
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12
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Association of dietary diversity changes and mortality among older people: A prospective cohort study. Clin Nutr 2021; 40:2620-2629. [PMID: 33933728 DOI: 10.1016/j.clnu.2021.04.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/30/2021] [Accepted: 04/06/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND & AIMS The association between dietary diversity (DD) changes and mortality remains unclear. We aimed to investigate the association between DD changes and all-cause mortality among older people. METHODS A total of 17,959 participants with a mean age of 84.8 years old were enrolled at baseline. Food groups were collected at baseline and follow-up using simplified food frequency questionnaire (FFQ), and then overall, plant-based and animal-based dietary diversity score (DDS) were calculated. DDS changes were calculated using DDS at baseline and the first follow-up. The association between three DDS changes (overall, plant-based and animal-based DDS) and subsequent all-cause mortality were evaluated. Nonparametrically restricted cubic splines and a multivariable-adjusted Cox proportional hazards model were used to estimate HRs and 95% CIs. RESULTS We documented 12,974 deaths over a 129,590 person-years of follow up. Compared with high-to-high DDS pattern, participants with lower overall DDS patterns had increased mortality risk with HRs (95%CI) of 1.39 (1.29-1.49), 1.53 (1.37-1.70), 1.38 (1.18-1.60) and 1.55 (1.31-1.83) for medium-to-medium, low-to-low, low-to-high and high-to-low patterns, respectively. And compared with high-to-high DDS pattern, the estimates were 1.34 (1.23-1.46), 1.49 (1.35-1.65), 1.43 (1.23-1.67) and 1.62 (1.40-1.88) for plant-based DDS, and 1.23 (1.15-1.31), 1.29 (1.20-1.40), 1.24 (1.12-1.37) and 1.28 (1.15-1.44) for animal-based DDS for medium-to-medium, low-to-low, low-to-high and high-to-low patterns, respectively. There was a U-shaped association between DDS change scores and mortality, and compared with participants with whose DDS remained stable, those with extreme declines and extreme improvements had higher risks of mortality with HRs (95% CI) of 1.15 (1.09-1.22) and 1.11 (1.04-1.17). CONCLUSIONS Maintaining a lower DDS, extreme declines and extreme improvements in DDS were all associated with an increased risk of all-cause mortality.
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13
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Molina P, Molina MD, Pallardó LM, Torralba J, Escudero V, Álvarez L, Peris A, Sánchez-Pérez P, González-Rico M, Puchades MJ, Fernández-Nájera JE, Giménez-Civera E, D'Marco L, Carrero JJ, Górriz JL. Disorders in bone-mineral parameters and the risk of death in persons with chronic kidney disease stages 4 and 5: the PECERA study. J Nephrol 2021; 34:1189-1199. [PMID: 33394344 DOI: 10.1007/s40620-020-00916-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 11/11/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Abnormalities of bone mineral parameters are associated with increased mortality in patients on dialysis, but their effects and the optimal range of these biomarkers are less well characterized in non-dialysis chronic kidney disease (CKD). METHODS PECERA (Collaborative Study Project in Patients with Advanced CKD) is a 3-year, prospective multicenter, open-cohort study of 966 adult patients with non-dialyzed CKD stages 4-5 enrolled from 12 centers in Spain. Associations between levels of serum calcium (Ca) (corrected for albumin), phosphate (P), and intact parathyroid hormone (iPTH) with all-cause mortality (primary outcome) and cardiovascular mortality (secondary outcome) were examined using time-dependent Cox proportional hazards models and penalized splines analysis adjusted by demographics and comorbidities, treatments and biochemical values collected every 6 months for 3 years. RESULTS After a median follow-up of 29 months (IQR: 13-36 months) there were 181 deaths (19%). The association of calcium with all-cause mortality was J-shaped, with an increased risk for all-cause mortality at levels > 10.5 mg/dL. For phosphate and iPTH levels, the association was U-shaped. The serum values associated with the minimum risk of mortality were 3.8 mg/dL for phosphate and 70 pg/mL for iPTH, being the lowest risk ranges between 2.8 and 5.0 mg/dL, and between 38 and 112 pg/mL for phosphate and iPTH, respectively. CONCLUSIONS Our study provides evidence on the non-linear association of serum calcium, phosphate and iPTH levels with mortality in stage 4 and 5 CKD patients, and suggests potential survival benefits for controlling bone mineral parameters in this population, as previously reported for dialysis patients.
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Affiliation(s)
- Pablo Molina
- Department of Nephrology, Hospital Universitari Dr Peset, FISABIO, Avda. Gaspar Aguilar, 90, 46017, Valencia, Spain.
- Department of Medicine, Universitat de València, Valencia, Spain.
| | - Mariola D Molina
- Department of Mathematics, Universidad de Alicante, Alicante, Spain
| | - Luis M Pallardó
- Department of Nephrology, Hospital Universitari Dr Peset, FISABIO, Avda. Gaspar Aguilar, 90, 46017, Valencia, Spain
- Department of Medicine, Universitat de València, Valencia, Spain
| | - Javier Torralba
- Department of Nephrology, Hospital General Universitario, Alicante, Spain
| | - Verónica Escudero
- Department of Nephrology, Hospital Universitari Dr Peset, FISABIO, Avda. Gaspar Aguilar, 90, 46017, Valencia, Spain
| | - Luis Álvarez
- Section of Nephrology, Hospital Virgen de Los Lirios, Alcoi, Spain
| | - Ana Peris
- Department of Nephrology, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Pilar Sánchez-Pérez
- Department of Nephrology, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Miguel González-Rico
- Department of Nephrology, Hospital Clínico Universitario, INCLIVA, Valencia, Spain
| | - María J Puchades
- Department of Nephrology, Hospital Clínico Universitario, INCLIVA, Valencia, Spain
| | | | - Elena Giménez-Civera
- Department of Nephrology, Hospital Clínico Universitario, INCLIVA, Valencia, Spain
| | - Luis D'Marco
- Department of Nephrology, Hospital Clínico Universitario, INCLIVA, Valencia, Spain
| | - Juan J Carrero
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - José L Górriz
- Department of Medicine, Universitat de València, Valencia, Spain
- Department of Nephrology, Hospital Clínico Universitario, INCLIVA, Valencia, Spain
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14
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Lv Y, Kraus VB, Gao X, Yin Z, Zhou J, Mao C, Duan J, Zeng Y, Brasher MS, Shi W, Shi X. Higher dietary diversity scores and protein-rich food consumption were associated with lower risk of all-cause mortality in the oldest old. Clin Nutr 2020; 39:2246-2254. [PMID: 31685303 PMCID: PMC7182467 DOI: 10.1016/j.clnu.2019.10.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 06/17/2019] [Accepted: 10/07/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Dietary diversity is widely advocated in national and international recommendations although whether the beneficial effects on survival or longevity still apply in the final phase of the lifespan remains understudied. We aimed to prospectively examine the association of dietary diversity, food items with all-cause mortality among the oldest old (80+) and determine whether dietary diversity recommendations were appropriate for this population. METHODS The study included 28,790 participants aged 80+ (9957 octogenarians, 9925 nonagenarians, and 8908 centenarians). A baseline dietary diversity score (DDS) was constructed based on nine food items of a food frequency questionnaire. Cox models with penalized splines evaluated non-linear associations of DDS as continuous variable with mortality to identify cut-offs of DDS. RESULTS We documented 23,503 deaths during 96,739 person-years of follow-up. Each one unit increase in DDS was associated with a 9% lower risk of mortality (adjusted hazard ratio (HR): 0.91; 95% confidential interval (CI): 0.90-0.92). Compared to participants whose DDS less than 2 scores, those with a DDS of 2, 3, 4, 5, and higher than 6 scores had a lower mortality risk, the HRs were 0.86 (0.82-0.89), 0.78 (0.75-0.81), 0.69 (0.66-0.72), 0.65 (0.62-0.68), and 0.56 (0.53-0.58) respectively, and a significant trend emerged (p < 0.001). Protein-rich food items were associated with prominent beneficial effects on mortality including meat (HR and 95% CI for high vs low frequency: 0.70 (0.68-0.72)), fish and sea food (HR, 0.74 (0.72-0.77)), egg (HR, 0.75 (0.73-0.77)), and bean (HR, 0.80 (0.78-0.82)). CONCLUSIONS Even after the age of 80, the DDS tool may offer a simple and straightforward mean of identifying and screening individuals at high risk for mortality. Recommendation of dietary diversity, especially consumption of protein-rich food, may be advocated to reduce mortality risk and promote longevity in the oldest old.
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Affiliation(s)
- Yuebin Lv
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Virginia Byers Kraus
- Duke Molecular Physiology Institute and Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Xiang Gao
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Zhaoxue Yin
- Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jinhui Zhou
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Chen Mao
- Division of Epidemiology, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Jun Duan
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Yi Zeng
- Center for the Study of Aging and Human Development and the Geriatric Division of School of Medicine, Duke University, Durham, NC, USA; Center for Study of Healthy Aging and Development Studies, Peking University, Beijing, China
| | - Melanie Sereny Brasher
- Department of Sociology and Anthropology and Department of Human Development and Family Studies, University of Rhode Island, Kingston, RI, USA
| | - Wanying Shi
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaoming Shi
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China.
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15
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Li FR, Zhang XR, Zhong WF, Li ZH, Gao X, Kraus VB, Lv YB, Zou MC, Chen GC, Chen PL, Zhang MY, Kur AKA, Shi XM, Wu XB, Mao C. Glycated Hemoglobin and All-Cause and Cause-Specific Mortality Among Adults With and Without Diabetes. J Clin Endocrinol Metab 2019; 104:3345-3354. [PMID: 30896760 PMCID: PMC7328059 DOI: 10.1210/jc.2018-02536] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 03/15/2019] [Indexed: 12/25/2022]
Abstract
CONTEXT The patterns of associations between glycated Hb (HbA1c) and mortality are still unclear. OBJECTIVE To explore the extent to which ranges of HbA1c levels are associated with the risk of mortality among participants with and without diabetes. DESIGN, SETTING, AND PATIENTS This was a nationwide, community-based prospective cohort study. Included were 15,869 participants (median age 64 years) of the Health and Retirement Study, with available HbA1c data and without a history of cancer. Cox proportional hazards regression models were used to estimate hazard ratios with 95% CIs for mortality. RESULTS A total of 2133 participants died during a median follow-up of 5.8 years. In participants with diabetes, those with an HbA1c level of 6.5% were at the lowest risk of all-cause mortality. When HbA1c level was <5.6% or >7.4%, the increased all-cause mortality risk became statistically significant as compared with an HbA1c level of 6.5%. As for participants without diabetes, those with an HbA1c level of 5.4% were at the lowest risk of all-cause mortality. When the HbA1c level was <5.0%, the increased all-cause mortality risk became statistically significant as compared with an HbA1c level of 5.4%. However, we did not observe a statistically significant elevated risk of all-cause mortality above an HbA1c level of 5.4%. CONCLUSIONS A U-shaped and reverse J-shaped association for all-cause mortality was found among participants with and without diabetes. The corresponding optimal ranges for overall survival are predicted to be 5.6% and 7.4% and 5.0% and 6.5%, respectively.
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Affiliation(s)
- Fu-Rong Li
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Xi-Ru Zhang
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Wen-Fang Zhong
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Zhi-Hao Li
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Xiang Gao
- Nutritional Epidemiology Laboratory, The Pennsylvania State University, Philadelphia, Pennsylvania
| | - Virginia Byers Kraus
- Duke Molecular Physiology Institute and Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina
| | - Yue-Bin Lv
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Meng-Chen Zou
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Guo-Chong Chen
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| | - Pei-Liang Chen
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Min-Yi Zhang
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Akech Kuol Akech Kur
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
| | - Xiao-Ming Shi
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xian-Bo Wu
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
- Correspondence and Reprint Requests: Chen Mao, PhD, or Xian-Bo Wu, PhD, Department of Epidemiology, School of Public Health, Southern Medical University, 510000 Guangzhou, Guangdong, China. E-mail: or
| | - Chen Mao
- Department of Epidemiology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), Guangzhou, China
- Correspondence and Reprint Requests: Chen Mao, PhD, or Xian-Bo Wu, PhD, Department of Epidemiology, School of Public Health, Southern Medical University, 510000 Guangzhou, Guangdong, China. E-mail: or
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16
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Lv YB, Gao X, Yin ZX, Chen HS, Luo JS, Brasher MS, Kraus VB, Li TT, Zeng Y, Shi XM. Revisiting the association of blood pressure with mortality in oldest old people in China: community based, longitudinal prospective study. BMJ 2018; 361:k2158. [PMID: 29871897 PMCID: PMC5987177 DOI: 10.1136/bmj.k2158] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To examine the associations of blood pressure with all cause mortality and cause specific mortality at three years among oldest old people in China. DESIGN Community based, longitudinal prospective study. SETTING 2011 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey, conducted in 22 Chinese provinces. PARTICIPANTS 4658 oldest old individuals (mean age 92.1 years). MAIN OUTCOME MEASURES All cause mortality and cause specific mortality assessed at three year follow-up. RESULTS 1997 deaths were recorded at three year follow-up. U shaped associations of mortality with systolic blood pressure, mean arterial pressure, and pulse pressure were identified; values of 143.5 mm Hg, 101 mm Hg, and 66 mm Hg conferred the minimum mortality risk, respectively. After adjustment for covariates, the U shaped association remained only for systolic blood pressure (minimum mortality risk at 129 mm Hg). Compared with a systolic blood pressure value of 129 mm Hg, risk of all cause mortality decreased for values lower than 107 mm Hg (from 1.47 (95% confidence interval 1.01 to 2.17) to 1.08 (1.01 to 1.17)), and increased for values greater than 154 mm Hg (from 1.08 (1.01 to 1.17) to 1.27 (1.02 to 1.58)). In the cause specific analysis, compared with a middle range of systolic blood pressure (107-154 mm Hg), higher values (>154 mm Hg) were associated with a higher risk of cardiovascular mortality (adjusted hazard ratio 1.51 (95% confidence interval 1.12 to 2.02)); lower values (<107 mm Hg) were associated with a higher risk of non-cardiovascular mortality (1.58 (1.26 to 1.98)). The U shaped associations remained in sensitivity and subgroup analyses. CONCLUSIONS This study indicates a U shaped association between systolic blood pressure and all cause mortality at three years among oldest old people in China. This association could be explained by the finding that higher systolic blood pressure predicted a higher risk of death from cardiovascular disease, and that lower systolic blood pressure predicted a higher risk of death from non-cardiovascular causes. These results emphasise the importance of revisiting blood pressure management or establishing specific guidelines for management among oldest old individuals.
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Affiliation(s)
- Yue-Bin Lv
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiang Gao
- Nutritional Epidemiology Lab, Pennsylvania State University, Philadelphia, PA, USA
| | - Zhao-Xue Yin
- Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hua-Shuai Chen
- Center for the study of Aging and Human Development and the Geriatric Division of School of Medicine, Duke University, Durham, NC, USA
| | - Jie-Si Luo
- Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Melanie Sereny Brasher
- Department of Sociology and Anthropology and Department of Human Development and Family Studies, University of Rhode Island, Kingston, RI, USA
| | - Virginia Byers Kraus
- Duke Molecular Physiology Institute and Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Tian-Tian Li
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yi Zeng
- Center for the study of Aging and Human Development and the Geriatric Division of School of Medicine, Duke University, Durham, NC, USA
- Center for Study of Healthy Aging and Development Studies, Peking University, Beijing, China
| | - Xiao-Ming Shi
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
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Huang Z, Zhang H, Boss J, Goutman SA, Mukherjee B, Dinov ID, Guan Y. Complete hazard ranking to analyze right-censored data: An ALS survival study. PLoS Comput Biol 2017; 13:e1005887. [PMID: 29253881 PMCID: PMC5749893 DOI: 10.1371/journal.pcbi.1005887] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 01/02/2018] [Accepted: 11/21/2017] [Indexed: 12/11/2022] Open
Abstract
Survival analysis represents an important outcome measure in clinical research and clinical trials; further, survival ranking may offer additional advantages in clinical trials. In this study, we developed GuanRank, a non-parametric ranking-based technique to transform patients' survival data into a linear space of hazard ranks. The transformation enables the utilization of machine learning base-learners including Gaussian process regression, Lasso, and random forest on survival data. The method was submitted to the DREAM Amyotrophic Lateral Sclerosis (ALS) Stratification Challenge. Ranked first place, the model gave more accurate ranking predictions on the PRO-ACT ALS dataset in comparison to Cox proportional hazard model. By utilizing right-censored data in its training process, the method demonstrated its state-of-the-art predictive power in ALS survival ranking. Its feature selection identified multiple important factors, some of which conflicts with previous studies.
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Affiliation(s)
- Zhengnan Huang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States of America
| | - Hongjiu Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States of America
| | - Jonathan Boss
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, United States of America
| | - Stephen A. Goutman
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America
| | - Bhramar Mukherjee
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, United States of America
| | - Ivo D. Dinov
- Department of Health Behavior and Biological Sciences, University of Michigan, Ann Arbor, MI, United States of America
- Statistics Online Computational Resource, University of Michigan, Ann Arbor, MI, United States of America
- Michigan Institute for Data Science, University of Michigan, Ann Arbor, MI, United States of America
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, United States of America
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States of America
- Department of Electronic Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States of America
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18
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Chang YM, Shen PS, Chen CS. Adaptive-Cox model averaging for right-censored data. COMMUN STAT-THEOR M 2017. [DOI: 10.1080/03610926.2016.1208237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Yu-Mei Chang
- Department of Statistics, Tunghai University, Taichung, Taiwan
| | - Pao-Sheng Shen
- Department of Statistics, Tunghai University, Taichung, Taiwan
| | - Chun-Shu Chen
- Institute of Statistics and Information Science, National Changhua University of Education, Changhua, Taiwan
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19
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Estimating and Interpreting Effects from Nonlinear Exposure-Response Curves in Occupational Cohorts Using Truncated Power Basis Expansions and Penalized Splines. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2017; 2017:7518035. [PMID: 29312462 PMCID: PMC5632483 DOI: 10.1155/2017/7518035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/25/2017] [Accepted: 05/16/2017] [Indexed: 11/29/2022]
Abstract
Truncated power basis expansions and penalized spline methods are demonstrated for estimating nonlinear exposure-response relationships in the Cox proportional hazards model. R code is provided for fitting models to get point and interval estimates. The method is illustrated using a simulated data set under a known exposure-response relationship and in a data application examining risk of carpal tunnel syndrome in an occupational cohort.
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20
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Tejero E, Prats E, Casitas R, Galera R, Pardo P, Gavilán A, Martínez-Cerón E, Cubillos-Zapata C, Del Peso L, García-Río F. Classification of Airflow Limitation Based on z-Score Underestimates Mortality in Patients with Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 2017; 196:298-305. [PMID: 28306326 DOI: 10.1164/rccm.201611-2265oc] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Global Lung Function Initiative recommends reporting lung function measures as z-score, and a classification of airflow limitation (AL) based on this parameter has recently been proposed. OBJECTIVES To evaluate the prognostic capacity of the AL classifications based on z-score or percentage predicted of FEV1 in patients with chronic obstructive pulmonary disease (COPD). METHODS A cohort of 2,614 patients with COPD recruited outside the hospital setting was examined after a mean (± SD) of 57 ± 13 months of follow-up, totaling 10,322 person-years. All-cause mortality was analyzed, evaluating the predictive capacity of several AL staging systems. MEASUREMENTS AND MAIN RESULTS Based on Global Initiative for Chronic Obstructive Lung Disease guidelines, 461 patients (17.6%) had mild, 1,452 (55.5%) moderate, 590 (22.6%) severe, and 111 (4.2%) very severe AL. According to z-score classification, 66.3% of patients remained with the same severity, whereas 23.7% worsened and 10.0% improved. Unlike other staging systems, patients with severe AL according to z-score had higher mortality than those with very severe AL (increase of risk by 5.2 and 3.9 times compared with mild AL, respectively). The predictive capacity for 5-year survival was slightly higher for FEV1 expressed as percentage of predicted than as z-score (area under the curve: 0.714-0.760 vs. 0.649-0.708, respectively). A severity-dependent relationship between AL grades by z-score and mortality was only detected in patients younger than age 60 years. CONCLUSIONS In patients with COPD, the AL classification based on z-score predicts worse mortality than those based on percentage of predicted. It is possible that the z-score underestimates AL severity in patients older than 60 years of age with severe functional impairment.
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Affiliation(s)
| | - Eva Prats
- 2 Unidad de Neumología, Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain
| | - Raquel Casitas
- 3 Servicio de Neumología and.,4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Raúl Galera
- 3 Servicio de Neumología and.,4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | | | - Adelaida Gavilán
- 2 Unidad de Neumología, Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain
| | - Elisabet Martínez-Cerón
- 3 Servicio de Neumología and.,4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Carolina Cubillos-Zapata
- 4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Del Peso
- 4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,6 Departamento de Bioquímica and.,7 Instituto de Investigaciones Biomédicas "Alberto Sols," Madrid, Spain
| | - Francisco García-Río
- 3 Servicio de Neumología and.,4 Instituto de Investigación Sanitaria, Hospital Universitario La Paz, Madrid, Spain.,5 Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.,8 Departamento de Medicina, Universidad Autónoma de Madrid, Madrid, Spain; and
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21
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Park S, Kang E, Park S, Kim YC, Han SS, Ha J, Kim DK, Kim S, Park SK, Han DJ, Lim CS, Kim YS, Lee JP, Kim YH. Metabolic Acidosis and Long-Term Clinical Outcomes in Kidney Transplant Recipients. J Am Soc Nephrol 2016; 28:1886-1897. [PMID: 28031407 DOI: 10.1681/asn.2016070793] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 11/23/2016] [Indexed: 01/07/2023] Open
Abstract
Metabolic acidosis (MA), indicated by low serum total CO2 (TCO2) concentration, is a risk factor for mortality and progressive renal dysfunction in CKD. However, the long-term effects of MA on kidney transplant recipients (KTRs) are unclear. We conducted a multicenter retrospective cohort study of 2318 adult KTRs, from January 1, 1997 to March 31, 2015, to evaluate the prevalence of MA and the relationships between TCO2 concentration and clinical outcomes. The prevalence of low TCO2 concentration (<22 mmol/L) began to increase in KTRs with eGFR<60 ml/min per 1.73 m2 and ranged from approximately 30% to 70% in KTRs with eGFR<30 ml/min per 1.73 m2 Multivariable Cox proportional hazards models revealed that low TCO2 concentration 3 months after transplant associated with increased risk of graft loss (hazard ratio [HR], 1.74%; 95% confidence interval [95% CI], 1.26 to 2.42) and death-censored graft failure (DCGF) (HR, 1.66; 95% CI, 1.14 to 2.42). Cox regression models using time-varying TCO2 concentration additionally demonstrated significant associations between low TCO2 concentration and graft loss (HR, 3.48; 95% CI, 2.47 to 4.90), mortality (HR, 3.16; 95% CI, 1.77 to 5.62), and DCGF (HR, 3.17; 95% CI, 2.12 to 4.73). Marginal structural Cox models adjusted for time-varying eGFR further verified significant hazards of low TCO2 concentration for graft loss, mortality, and DCGF. In conclusion, MA was frequent in KTRs despite relatively preserved renal function and may be a significant risk factor for graft failure and patient mortality, even after adjusting for eGFR.
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Affiliation(s)
| | | | | | | | | | - Jongwon Ha
- Surgery, Seoul National University College of Medicine, Seoul, Korea
| | | | | | | | - Duck Jong Han
- Division of Kidney Transplantation, Department of Surgery, Asan Medical Center and University of Ulsan College of Medicine, Seoul, Korea; and
| | - Chun Soo Lim
- Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | | | - Jung Pyo Lee
- Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Young Hoon Kim
- Division of Kidney Transplantation, Department of Surgery, Asan Medical Center and University of Ulsan College of Medicine, Seoul, Korea; and
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Roshani D, Ghaderi E. Comparing Smoothing Techniques for Fitting the Nonlinear Effect of Covariate in Cox Models. Acta Inform Med 2016; 24:38-41. [PMID: 27041809 PMCID: PMC4789637 DOI: 10.5455/aim.2016.24.38-41] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 01/15/2016] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Cox model is a popular model in survival analysis, which assumes linearity of the covariate on the log hazard function, While continuous covariates can affect the hazard through more complicated nonlinear functional forms and therefore, Cox models with continuous covariates are prone to misspecification due to not fitting the correct functional form for continuous covariates. In this study, a smooth nonlinear covariate effect would be approximated by different spline functions. MATERIAL AND METHODS We applied three flexible nonparametric smoothing techniques for nonlinear covariate effect in the Cox models: penalized splines, restricted cubic splines and natural splines. Akaike information criterion (AIC) and degrees of freedom were used to smoothing parameter selection in penalized splines model. The ability of nonparametric methods was evaluated to recover the true functional form of linear, quadratic and nonlinear functions, using different simulated sample sizes. Data analysis was carried out using R 2.11.0 software and significant levels were considered 0.05. RESULTS Based on AIC, the penalized spline method had consistently lower mean square error compared to others to selection of smoothed parameter. The same result was obtained with real data. CONCLUSION Penalized spline smoothing method, with AIC to smoothing parameter selection, was more accurate in evaluate of relation between covariate and log hazard function than other methods.
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Affiliation(s)
- Daem Roshani
- Social Determinants of Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran; Department of Epidemiology and Biostatistics, Medical School, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Ebrahim Ghaderi
- Social Determinants of Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran; Department of Epidemiology and Biostatistics, Medical School, Kurdistan University of Medical Sciences, Sanandaj, Iran
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23
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Donoghoe MW, Marschner IC. Flexible regression models for rate differences, risk differences and relative risks. Int J Biostat 2016; 11:91-108. [PMID: 25781711 DOI: 10.1515/ijb-2014-0044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Generalized additive models (GAMs) based on the binomial and Poisson distributions can be used to provide flexible semi-parametric modelling of binary and count outcomes. When used with the canonical link function, these GAMs provide semi-parametrically adjusted odds ratios and rate ratios. For adjustment of other effect measures, including rate differences, risk differences and relative risks, non-canonical link functions must be used together with a constrained parameter space. However, the algorithms used to fit these models typically rely on a form of the iteratively reweighted least squares algorithm, which can be numerically unstable when a constrained non-canonical model is used. We describe an application of a combinatorial EM algorithm to fit identity link Poisson, identity link binomial and log link binomial GAMs in order to estimate semi-parametrically adjusted rate differences, risk differences and relative risks. Using smooth regression functions based on B-splines, the method provides stable convergence to the maximum likelihood estimates, and it ensures that the estimates always remain within the parameter space. It is also straightforward to apply a monotonicity constraint to the smooth regression functions. We illustrate the method using data from a clinical trial in heart attack patients.
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24
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Mortality prediction in chronic obstructive pulmonary disease comparing the GOLD 2007 and 2011 staging systems: a pooled analysis of individual patient data. THE LANCET RESPIRATORY MEDICINE 2015; 3:443-50. [PMID: 25995071 DOI: 10.1016/s2213-2600(15)00157-5] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/14/2015] [Accepted: 04/21/2015] [Indexed: 12/28/2022]
Abstract
BACKGROUND There is no universal consensus on the best staging system for chronic obstructive pulmonary disease (COPD). Although documents (eg, the Global Initiative for Chronic Obstructive Lung Disease [GOLD] 2007) have traditionally used forced expiratory volume in 1 s (FEV1) for staging, clinical parameters have been added to some guidelines (eg, GOLD 2011) to improve patient management. As part of the COPD Cohorts Collaborative International Assessment (3CIA) initiative, we aimed to investigate how individual patients were categorised by GOLD 2007 and 2011, and compare the prognostic accuracy of the staging documents for mortality. METHODS We searched reports published from Jan 1, 2008, to Dec 31, 2014. Using data from cohorts that agreed to participate and had a minimum amount of information needed for GOLD 2007 and 2011, we did a patient-based pooled analysis of existing data. With use of raw data, we recalculated all participant assignments to GOLD 2007 I-IV classes, and GOLD 2011 A-D stages. We used survival analysis, C statistics, and non-parametric regression to model time-to-death data and compare GOLD 2007 and GOLD 2011 staging systems to predict mortality. FINDINGS We collected individual data for 15 632 patients from 22 COPD cohorts from seven countries, totalling 70 184 person-years. Mean age of the patients was 63·9 years (SD 10·1); 10 751 (69%) were men. Based on FEV1 alone (GOLD 2007), 2424 (16%) patients had mild (I), 7142 (46%) moderate (II), 4346 (28%) severe (III), and 1670 (11%) very severe (IV) disease. We compared staging with the GOLD 2007 document with that of the new GOLD 2011 system in 14 660 patients: 5548 (38%) were grade A, 2733 (19%) were grade B, 1835 (13%) were grade C, and 4544 (31%) were grade D. GOLD 2011 shifted the overall COPD severity distribution to more severe categories. There were nearly three times more COPD patients in stage D than in former stage IV (p<0·05). The predictive capacity for survival up to 10 years was significant for both systems (p<0·01) but area under the curves were only 0·623 (GOLD 2007) and 0·634 (GOLD 2011), and GOLD 2007 and 2011 did not differ significantly. We identified the percent predicted FEV1 thresholds of 85%, 55% and 35% as better to stage COPD severity for mortality, which are similar to the ones used previously. INTERPRETATION Neither GOLD COPD classification schemes have sufficient discriminatory power to be used clinically for risk classification at the individual level to predict total mortality for 3 years of follow-up and onwards. Increasing intensity of treatment of patients with COPD due to their GOLD 2011 reclassification is not known to improve health outcomes. Evidence-based thresholds should be searched when exploring the prognostic ability of current and new COPD multicomponent indices. FUNDING None.
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25
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Fernández-Martín JL, Martínez-Camblor P, Dionisi MP, Floege J, Ketteler M, London G, Locatelli F, Gorriz JL, Rutkowski B, Ferreira A, Bos WJ, Covic A, Rodríguez-García M, Sánchez JE, Rodríguez-Puyol D, Cannata-Andia JB. Improvement of mineral and bone metabolism markers is associated with better survival in haemodialysis patients: the COSMOS study. Nephrol Dial Transplant 2015; 30:1542-51. [PMID: 25920921 DOI: 10.1093/ndt/gfv099] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/17/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Abnormalities in serum phosphorus, calcium and parathyroid hormone (PTH) have been associated with poor survival in haemodialysis patients. This COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis assesses the association of high and low serum phosphorus, calcium and PTH with a relative risk of mortality. Furthermore, the impact of changes in these parameters on the relative risk of mortality throughout the 3-year follow-up has been investigated. METHODS COSMOS is a 3-year, multicentre, open-cohort, prospective study carried out in 6797 adult chronic haemodialysis patients randomly selected from 20 European countries. RESULTS Using Cox proportional hazard regression models and penalized splines analysis, it was found that both high and low serum phosphorus, calcium and PTH were associated with a higher risk of mortality. The serum values associated with the minimum relative risk of mortality were 4.4 mg/dL for serum phosphorus, 8.8 mg/dL for serum calcium and 398 pg/mL for serum PTH. The lowest mortality risk ranges obtained using as base the previous values were 3.6-5.2 mg/dL for serum phosphorus, 7.9-9.5 mg/dL for serum calcium and 168-674 pg/mL for serum PTH. Decreases in serum phosphorus and calcium and increases in serum PTH in patients with baseline values of >5.2 mg/dL (phosphorus), >9.5 mg/dL (calcium) and <168 pg/mL (PTH), respectively, were associated with improved survival. CONCLUSIONS COSMOS provides evidence of the association of serum phosphorus, calcium and PTH and mortality, and suggests survival benefits of controlling chronic kidney disease-mineral and bone disorder biochemical parameters in CKD5D patients.
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Affiliation(s)
- José Luis Fernández-Martín
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Oviedo, Asturias, Spain
| | - Pablo Martínez-Camblor
- Oficina de Investigación Biosanitaria de Asturias (OIB), Asturias, Spain Universidad Autónoma de Chile, Chile
| | - María Paula Dionisi
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Oviedo, Asturias, Spain
| | - Jürgen Floege
- Department of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | | | | | - Francesco Locatelli
- Department of Nephrology, Dialysis and Renal Transplant, Alessandro Manzoni Hospital, Lecco, Italy
| | | | - Boleslaw Rutkowski
- Department of Nephrology, Transplantology and Internal Medicine, Gdañsk Medical University, Gdansk, Poland
| | - Aníbal Ferreira
- Nephrology Department, Hospital Curry Cabral and Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Willem-Jan Bos
- Department of Internal Medicine, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - Adrian Covic
- University of Medicine 'Gr. T. Popa', Iasi, Romania
| | - Minerva Rodríguez-García
- Department of Nephrology, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Oviedo, Asturias, Spain
| | - José Emilio Sánchez
- Department of Nephrology, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Oviedo, Asturias, Spain
| | - Diego Rodríguez-Puyol
- Department of Medicine, Universidad de Alcalá Nephrology Section and Research Unit Foundation, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Spain IRSIN REDinREN (Instituto de Salud Carlos III), Madrid, Spain
| | - Jorge B Cannata-Andia
- Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Oviedo, Asturias, Spain
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Hendry DJ. Data generation for the Cox proportional hazards model with time-dependent covariates: a method for medical researchers. Stat Med 2014; 33:436-54. [PMID: 24014094 DOI: 10.1002/sim.5945] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 07/23/2013] [Indexed: 11/07/2022]
Abstract
The proliferation of longitudinal studies has increased the importance of statistical methods for time-to-event data that can incorporate time-dependent covariates. The Cox proportional hazards model is one such method that is widely used. As more extensions of the Cox model with time-dependent covariates are developed, simulations studies will grow in importance as well. An essential starting point for simulation studies of time-to-event models is the ability to produce simulated survival times from a known data generating process. This paper develops a method for the generation of survival times that follow a Cox proportional hazards model with time-dependent covariates. The method presented relies on a simple transformation of random variables generated according to a truncated piecewise exponential distribution and allows practitioners great flexibility and control over both the number of time-dependent covariates and the number of time periods in the duration of follow-up measurement. Within this framework, an additional argument is suggested that allows researchers to generate time-to-event data in which covariates change at integer-valued steps of the time scale. The purpose of this approach is to produce data for simulation experiments that mimic the types of data structures applied that researchers encounter when using longitudinal biomedical data. Validity is assessed in a set of simulation experiments, and results indicate that the proposed procedure performs well in producing data that conform to the assumptions of the Cox proportional hazards model.
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Affiliation(s)
- David J Hendry
- Center for the Study of American Politics, Institution for Social and Policy Studies, Yale University, New Haven, CT 06520-8209, U.S.A
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27
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Vogtmann E, Xiang YB, Li HL, Levitan EB, Yang G, Waterbor JW, Gao J, Cai H, Xie L, Wu QJ, Zhang B, Gao YT, Zheng W, Shu XO. Fruit and vegetable intake and the risk of colorectal cancer: results from the Shanghai Men's Health Study. Cancer Causes Control 2013; 24:1935-45. [PMID: 23913012 DOI: 10.1007/s10552-013-0268-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/26/2013] [Indexed: 12/20/2022]
Abstract
PURPOSE The observed associations of fruit and vegetable consumption with the risk of colorectal cancer have been inconsistent. Therefore, we aimed to evaluate the association of fruit and vegetable consumption with the risk of colorectal cancer among Chinese men. METHODS 61,274 male participants aged 40-74 years were included. A validated food frequency questionnaire was administered to collect information on usual dietary intake, including 8 fruits and 38 vegetables commonly consumed by residents of Shanghai. Follow-up for diagnoses of colon or rectal cancer was available through 31 December 2010. Dietary intakes were analyzed both as categorical and continuous variables. Multivariable-adjusted hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) were calculated for colorectal, colon, and rectal cancers using Cox proportional hazards models. RESULTS After 390,688 person-years of follow-up, 398 cases of colorectal cancer (236 colon and 162 rectal) were observed in the cohort. Fruit consumption was inversely associated with the risk of colorectal cancer (fifth vs. first quintile HR 0.67; 95 % CI 0.48, 0.95; p trend = 0.03), whereas vegetable intake was not significantly associated with risk. The associations for subgroups of fruits and legumes, but not other vegetable categories, were generally inversely associated with the risk of colon and rectal cancers. CONCLUSIONS Fruit intake was generally inversely associated with the risk of colorectal cancer, whereas vegetable consumption was largely unrelated to risk among middle-aged and older Chinese men.
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Affiliation(s)
- Emily Vogtmann
- Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, 37203, USA
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Abstract
Seasonality is a long-recognized attribute of many viral infections of humans, but the mechanisms underlying seasonality, particularly for person-to-person communicable diseases, remain poorly understood. Better understanding of drivers of seasonality could provide insights into the relationship between the physical environment and infection risk, which is particularly important in the context of global ecological change in general, and climate change in particular. In broad terms, seasonality represents oscillation in pathogens' effective reproductive number, which, in turn, must reflect oscillatory changes in infectiousness, contact patterns, pathogen survival, or host susceptibility. Epidemiological challenges to correct identification of seasonal drivers of risk include failure to adjust for predictable correlation between disease incidence and seasonal exposures, and unmeasured confounding. The existing evidence suggests that the seasonality of some enteric and respiratory viral pathogens may be driven by enhanced wintertime survival of pathogens, and also by increased host susceptibility resulting from relative 'wintertime immune suppression'. For vector-borne diseases and zoonoses, environmental influences on vector or reservoir abundance, and vector biting rates, are probably more important. However, numerous areas of uncertainty exist, making this an exciting area for future research.
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Affiliation(s)
- D Fisman
- The Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
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29
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Kim YJ. A comparative study of nonparametric estimation in Weibull regression: A penalized likelihood approach. Comput Stat Data Anal 2011. [DOI: 10.1016/j.csda.2010.10.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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