What is a cohort effect? Comparison of three statistical methods for modeling cohort effects in obesity prevalence in the United States, 1971-2006

Aging-related changes in protein and fat intake and their related meal types factors by longitudinal birth cohort analysis using the National Health and Nutrition Survey in Japan from 2001 to 2019

BACKGROUND

To provide seamless nutritional support from early adulthood to late adulthood in Japan, this study aimed to identify aging-related changes in protein and fat intake and meal types.

METHODS

Birth cohort analysis was conducted in this study. The protein intake, protein-to-energy ratio, fat intake, and fat-to-energy ratio in men and women from their 20s to 60s in 2001 was calculated using the data of the National Health and Nutrition Survey in Japan between 2001 and 2019 (n = 139,876, 47.0% men, mean age: 54.9 and 55.4 years for men and women, respectively). The intakes were calculated for every subsequent year, the aging-related changes were identified by age group, and the 99 food groups were classified into staple-focused meal types through factor analysis. The weighted average component value per 1 g of each food group was calculated, multiplied by the food weight, and totaled to determine the mean intake by meal type and to confirm the aging-related changes. The year when the slope changed before and after was identified through Joinpoint regression analysis.

RESULTS

The protein intake, protein-to-energy ratio, fat intake, and fat-to-energy ratio initially declined or remained unchanged with aging in almost all generations (20s to 60s in 2001) but began to increase after 8-15 years. The food groups were classified into rice, noodle, and bread types. The protein and fat intake from the noodle type initially showed a decreasing trend but began to increase with aging after 8-15 years in almost all generations in both sexes (p < 0.05 for difference in slope).

CONCLUSIONS

The increase of protein intake and protein-to-energy ratio and fat intake and fat-to-energy ratio over time observed among Japanese adults may be related to the increased intake of food groups from noodle type meals. Thus, considering the type of staple food (i.e., rice, noodles, or bread) and its combination with other foods when adhering to a balanced diet is necessary.

Time Trends and Demographic Disparities in Helicobacter pylori Burden in a Large, Community-Based Population in the United States

Background and Aims

There are minimal recent population-based data on the epidemiology of Helicobacter pylori (H. pylori) in the United States.

Methods

This retrospective cohort study evaluated H. pylori positivity rates in adult members of a large, community-based US population in 2000-2019. Time trends, demographic disparities, and birth cohort effects on H. pylori test positivity rates were analyzed.

Results

Among 751,322 individuals tested for H. pylori, the overall nonserological and serological test positivity rates were 18.2% (95% confidence interval [CI], 18.1%-18.4%) and 36.8% (95% CI, 36.6%-36.9%), respectively. Nonserological positivity rate (95% CI) was significantly higher among Asian (23.2% [22.8%-23.6%]), Black (25.1% [24.4%-25.8%]), and Hispanic (28.1% [27.7%-28.5%]) individuals than non-Hispanic White individuals (10.0% [9.8%-10.2%]), and was significantly higher among individuals with a non-English language preference (32.9% [32.3%-33.5%]) than those with English language preference (15.8% [15.6%-15.9%]). Patterns were similar for serological positivity, although with substantially higher rates. Serological positivity rates decreased over 2 decades but nonserological positivity rates initially decreased and then stabilized over the past decade. There was a significant decrease in both nonserological and serological positivity rates from older to younger birth cohorts. Older age, non-White race or Hispanic ethnicity, male sex, and non-English language preference were associated with high odds of H. pylori positivity.

Conclusion

The burden of H. pylori decreased over 2 decades, although the rates of active infection plateaued over the past decade in a diverse, community-based US population, likely attributable to birth cohort effects and demographic changes. Asian, Black, and Hispanic individuals had 2-3-fold higher rates of active H. pylori infection than non-Hispanic White individuals. These findings should inform targeted screening and eradication of H. pylori in high-risk US populations.

Association between physician age and patterns of end-of-life care among older Americans

BACKGROUND

End-of-life (EOL) care patterns may differ by physician age given differences in how physicians are trained or changes associated with aging. We sought to compare patterns of EOL care delivered to older Americans according to physician age.

METHODS

We conducted a cross-sectional study of a 20% sample of Medicare fee-for-service beneficiaries aged ≥66 years who died in 2016-2019 (n = 487,293). We attributed beneficiaries to the physician who had >50% of primary care visits during the last 6 months of life. We compared beneficiary-level outcomes by physician age (<40, 40-49, 50-59, or ≥60) in two areas: (1) advance care planning (ACP) and palliative care; and (2) high-intensity care at the EOL.

RESULTS

Beneficiaries attributed to younger physicians had slightly higher proportions of billed ACP (adjusted proportions, 17.1%, 16.1%, 15.5%, and 14.0% for physicians aged <40, 40-49, 50-59, and ≥60, respectively; p-for-trend adjusted for multiple comparisons <0.001) and palliative care counseling or hospice use in the last 180 days of life (64.5%, 63.6%, 61.9%, and 60.8%; p-for-trend <0.001). Similarly, physicians' younger age was associated with slightly lower proportions of emergency department visits (57.4%, 57.0%, 57.4%, and 58.1%; p-for-trend <0.001), hospital admissions (51.2%, 51.1%, 51.4%, and 52.1%; p-for-trend <0.001), intensive care unit admissions (27.8%, 27.9%, 28.2%, and 28.3%; p-for-trend = 0.03), or mechanical ventilation or cardiopulmonary resuscitation (14.2, 14.9%, 15.2%, and 15.3%; p-for-trend <0.001) in the last 30 days of life, and in-hospital death (20.2%, 20.6%, 21.3%, and 21.5%; p-for-trend <0.001).

CONCLUSIONS

We found that differences in patterns of EOL care between beneficiaries cared for by younger and older physicians were small, and thus, not clinically meaningful. Future research is warranted to understand the factors that can influence patterns of EOL care provided by physicians, including initial and continuing medical education.

Differential age-specific associations of LDL cholesterol and body mass index with coronary heart disease

BACKGROUND AND AIMS

Low-density lipoprotein cholesterol (LDLc) and body mass index (BMI) are not always correlated and their relationship is probably dependent on age, indicating differential age-specific associations of these factors with health outcomes. We aim to discriminate the roles of LDLc and BMI in coronary heart disease (CHD) across different age groups.

METHODS

This is a prospective cohort study of 368,274 participants aged 38-73 years and free of CHD at baseline. LDLc and BMI were measured at baseline, and incident CHD was the main outcome. Cox proportional hazards model and restricted cubic spline (RCS) regression were used to estimate hazard ratio (HR) and 95% confidence interval (CI) of exposure on CHD.

RESULTS

After a mean of 12 years of follow-up, similar relationships of LDLc and BMI with CHD risk were observed in the overall population but in differential age-specific patterns. Across the age groups of <50, 50-54, 55-59, 60-64 and ≥ 65 years, the LDLc-CHD association diminished with the adjusted HRs decreasing from 1.35, 1.26, 1.19, 1.11 to 1.08; while no declining trend was found in BMI-CHD relationship with the adjusted HRs of 1.15, 1.11, 1.12, 1.13 and 1.15, respectively. The interaction and mediation between LDLc and BMI on CHD risk were more pronounced at young-age groups. LDLc-CHD but not BMI-CHD association was dependent on sex, metabolic syndrome and lipid-lowering drugs use.

CONCLUSIONS

There were differential age-specific associations of LDLc and BMI with the risk of developing CHD, calling for future efforts to discriminate the age-different benefits from lipids management or weight control on the primary prevention for CHD.

Exploring Disparities for Obesity in Korea Using Hierarchical Age-Period-Cohort Analysis With Cross-Classified Random Effect Models

BACKGROUND

This research article investigates the age, period, and birth cohort effects on prevalence of obesity in the Korean population, with the goal of identifying key factors to inform effective public health strategies.

METHODS

We analyzed data from the Korea National Health and Nutrition Examination Survey, spanning 2007-2021, including 35,736 men and 46,756 women. Using the hierarchical age-period-cohort (APC) analysis with cross-classified random effects modeling, we applied multivariable mixed logistic regression to estimate the marginal prevalence of obesity across age, period, and birth cohort, while assessing the interaction between APC and lifestyle and socioeconomic factors.

RESULTS

Our findings reveal an inverted U-shaped age effect on obesity, influenced by smoking history (P for interaction = 0.020) and physical activity (I for interaction < 0.001). The period effect was positive in 2020 and 2021, while negative in 2014 (P for period effect < 0.001). A declining trend in obesity prevalence was observed in birth cohorts from 1980s onward. Notably, disparities in obesity rates among recent birth cohorts have increased in relation to smoking history (P for interaction = 0.020), physical activity (P for interaction < 0.001), and residence (P for interaction = 0.005). Particularly, those born after 1960 were more likely to be obese if they were ex-smokers, physical inactive, or lived in rural areas.

CONCLUSION

These findings highlight growing disparities in obesity within birth cohorts, underscoring the need for targeted health policies that promote smoking cessation and physical activity, especially in rural areas.

Tobacco policies and changes in the tendency of smoking cessation in cigarette users in Chile: a longitudinal cross-sectional study

OBJECTIVE

To assess the impact of tobacco control regulations and policy implementation on smoking cessation tendencies in cigarette users born between 1982 and 1991 in Chile.

DESIGN

Longitudinal cross-sectional study.

SETTING

National level.

PARTICIPANTS

Data from the National Survey of Drug Consumption (Service of Prevention and Rehabilitation for Drug and Alcohol Consumption). A pseudo-cohort of smokers born between 1982 and 1991 (N=17 905) was tracked from 2002 to 2016.

PRIMARY AND SECONDARY OUTCOMES MEASURES

Primary outcome was the tendency to cease smoking conceptualised as the report of using cigarettes 1 month or more ago relative to using cigarettes in the last 30 days. The main exposure variable was the Tobacco Policy Index-tracking tobacco policy changes over time. Logistic regression, controlling for various factors, was applied.

RESULTS

Models suggested a 14% increase in the smoking cessation tendency of individuals using cigarettes 1 month or more ago relative to those using cigarettes in the last 30 days (OR 1.14, CI 95% CI 1.10 to 1.19) for each point increment in the Tobacco Policy index.

CONCLUSIONS

Our study contributes to documenting a positive impact of the implementation of interventions considered in the MPOWER strategy in the progression of smoking cessation tendencies in smokers born between 1982 and 1991 in Chile.

Birth cohort effects on diagnosed atrial fibrillation incidence: nationwide cohort study from 1980 to 2018

BACKGROUND

The incidence of atrial fibrillation (AF) shows substantial temporal trends, but the contribution of birth cohort effects is unknown. These effects refer to the relationship between birth year and the likelihood of developing AF. We aimed to assess trends in cumulative incidence of diagnosed AF across birth cohorts and to disentangle the effects of age, birth cohort and calendar period by using age-period-cohort analyses.

METHODS

In a Danish nationwide population-based cohort study, 4.7 million individuals were selected at a given index age (45, 55, 65 and 75 years) free of AF and followed up for diagnosed AF. For each index age, we assessed trends in 10-year cumulative incidence of AF across six 5-year birth cohorts. An age-period-cohort model was estimated using Poisson regression with constrained spline functions collapsing data into 1-year intervals across ages and calendar years.

RESULTS

Cumulative incidence of AF diagnosis increased across birth cohorts for all index ages (ptrend<0.001). Compared with the first birth cohort, the diagnosed AF incidence rate ratio in the last birth cohort was 3.0 (95% CI 2.9 to 3.2) for index age 45 years, 2.9 (2.8 to 3.0) for 55 years, 2.8 (2.7 to 2.8) for 65 years and 2.7 (2.6 to 2.7) for 75 years. Age-period-cohort analyses showed substantial birth cohort effects independent of age, with no clear period effect. Compared with individuals born in 1930, the diagnosed AF incidence rate was 0.125 smaller among individuals born in 1885 and was four times larger among individuals born in 1975.

CONCLUSION

Substantial birth cohort effects, independent of age and calendar period, influence trends in diagnosed AF incidence.

N-Terminal Pro-Brain Type Natriuretic Peptide Predicts Cardiovascular Events Independently of Arterial Stiffness, Assessed By Carotid-to-Femoral Pulse Wave Velocity, in Apparently Healthy Subjects

AIM

This study aimed to evaluate whether N-terminal pro-brain natriuretic peptide (NT-proBNP) and carotid-to-femoral pulse wave velocity (PWV) carried independent prognostic value in predicting cardiovascular events in apparently healthy individuals beyond traditional risk factors.

METHODS

A total of 1,872 participants aged 41, 51, 61, or 71 years from the MONItoring of trends and determinants in CArdiovascular disease (MONICA) study were included. Traditional risk factors were assessed, including: smoking status; mean systolic and diastolic blood pressure; body mass index; fasting plasma glucose; serum triglycerides; total, high-density, and low-density lipoprotein cholesterol; NT-proBNP; and PWV. The principal endpoint that was assessed during 16 years of follow-up was a composite of major adverse cardiovascular events (MACE). The secondary endpoints were cardiovascular mortality (CVM), hospitalisation for coronary artery disease (CAD), and a composite of hospitalisation for heart failure (HF) or atrial fibrillation (AF).

RESULTS

At baseline, NT-proBNP was associated with PWV (β=0.14; p<0.001), but not after adjustment for traditional risk factors (β=-0.01; p=0.67). In models including traditional risk factors and PWV, NT-proBNP was associated with all four outcomes (HRMACE=1.33, 95% CI 1.16-1.52; HRCVM=2.02, 95% CI 1.65-2.48; HRCAD=1.29, 95% CI 1.07-1.55; and HRHF or AF=1.79, 95% CI 1.40-2.28). In the same model, PWV was only associated with CVM (HRCVM=1.20, 95% CI 1.01-1.41). No interactions between NT-proBNP and PWV were found. N-terminal pro-brain natriuretic peptide significantly improved net reclassification (NRI) for MACE (NRI=0.12; p=0.03), CVM (NRI=0.33; p<0.001), and HF or AF (NRI=0.33; p<0.001) beyond traditional risk factors, while PWV did not aid in net reclassification improvement for any endpoint.

CONCLUSIONS

In apparently healthy individuals, NT-proBNP and PWV predicted cardiovascular events independently. N-terminal pro-brain natriuretic peptide improved reclassification for the prediction of MACE, CVM, and hospitalisation for HF or AF beyond traditional risk factors, while PWV did not.

Birth Cohort Colorectal Cancer (CRC): Implications for Research and Practice

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity-including and extending beyond rising EOCRC-can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology.

Trends and age-period-cohort effect on dental caries prevalence from 2008 to 2019 among Brazilian preschoolers

This study aimed to evaluate trends in the prevalence of dental caries in preschool children and associated factors considering different time variations. This is a time series study performed using data from three cross-sectional studies with pre-school children from southern Brazil in 2008, 2013 and 2019. This children group was born between the years of 2003 to 2018. Dental caries was evaluated by decayed, missing and filled deciduous teeth (dmft index). Demographic, socioeconomic, behavioural and psychosocial variables were also collected. Chi-square test for trends and a hierarchical age-period-cohort (HAPC) analysis using multilevel Poisson regression model for testing the associations between predictor variables and dental caries experience were used. A total of 1,644 pre-school children participated in all surveys. There was a significant difference in caries experience considering all APC effects. The prevalence of dental caries was 25.0% in 2008, 16.3% in 2013, and 19.4% in 2019 (p < 0.01) and no statistical difference was observed. An age effect showed that older children were more likely to experience dental caries. Considering the cohort effect, there is a significant difference between the generations, mainly between 2003 and 2018. Household income, use of dental services, and parent's perception of child oral health were associated with dental caries experience no matter the time variation. Despite recent declines in dental caries prevalence among preschool children, caries levels increased with age and social inequalities persisted through the years, indicating a need of reviewing the policies to reduce the burden of this oral disease.

Nurse-led approaches to address social determinants of health and advance health equity: A new framework and its implications

BACKGROUND

The U.S. health care system is burdened by inefficiencies, longstanding health inequities, and unstainable costs. Within the nursing profession and the broader health care sector, there is growing recognition of the need for a paradigm shift that addresses persistent structural problems and advances health equity.

PURPOSE

Despite evidence of the importance of the social determinants of health (SDOH) in shaping inequitable health outcomes, practical tools for applying SDOH theory in the development of effective nurse-led programs to mitigate harmful SDOH remain scarce.

METHODS

We synthesize extant SDOH literature into a heuristic framework for conceptualizing core SDOH mechanisms, constructs, and principles.

FINDINGS

To illustrate how nurse scientists can use the framework to guide the development of programs for SDOH mitigation, we outline a three-step exemplar application to the U.S. Latino HIV epidemic.

DISCUSSION

Our framework can inform a paradigm shift toward nurse-led, multi-level SDOH mitigation across practice, education, and research.

Age, period and cohort-related trends in prescription opioid use in the USA, 1999-2018

BACKGROUND

To provide insight into the longitudinal dynamics of opioid use throughout the overdose crisis, this study estimated the separate influences of age, period and cohort on prescription opioid use during 1999-2018 in the USA.

METHODS

Data from 10 cycles of the cross-sectional National Health and Nutrition Examination Survey were used to conduct an age-period-cohort analysis of the prevalence of prescription opioid use (n=63 500 across 1999-2018). Temporal trends were graphically visualised. The median polish approach was used to estimate age, period and cohort-related effects on prescription opioid use.

RESULTS

Prescription opioid use broadly increased across the lifespan, with steeper prevalence increases observed from young adulthood to mid-adulthood. Period-related variation was consistent with recognised nationwide declines in opioid prescribing. While there was no evidence of systematic cohort effects, compared with individuals born in 1951-1954, those born during 1963-1966 had greater prescription opioid use (prevalence ratio (PR)=1.23, 95% CI: 1.05 to 1.43), whereas the 1991-1994 and 1999-2002 cohorts had lower prescription opioid use (PR91-94=0.70, 95% CI: 0.50 to 0.98; PR99-02=0.72, 95% CI: 0.63 to 0.81).

CONCLUSION

In the USA, longitudinal trends in prescription opioid use during 1999-2018 were predominantly driven by age and period influences. The cohort of youngest baby boomers experienced greater prescription opioid use, whereas recent-born cohorts have had lower use. As the overdose crisis continues evolving, such population-level characterisations of age, period and cohort dynamics are instrumental in understanding opioid use and can inform prevention and intervention approaches by identifying population groups more likely to use opioids who, thus, may also experience related outcomes.

Epidemiologic Patterns of Autism Spectrum Disorder in Pediatric Inpatients in the United States, 1997-2019

The reported prevalence of autism spectrum disorder (ASD) has more than tripled in the past two decades in the United States, due in part to improved screening and diagnostic techniques. Epidemiologic data on ASD, however, are largely limited to population-based surveillance systems. We examined epidemiologic patterns in ASD diagnoses among inpatients aged 1-20 years, using data from the Kids' Inpatient Database (KID) from 1997 to 2019. ASD cases were identified using ICD-9-CM and ICD-10-CM codes. Of 9,267,881 hospital discharges studied, 110,090 (1.19%) had a diagnosis of ASD. The prevalence of ASD was higher among males compared to females (1.53% vs. 0.54%) and was highest among non-Hispanic Whites (1.28% vs. 0.95% in non-Hispanic Blacks, 0.94% in Hispanics, and 1.18% in Other races). ASD prevalence increased from 0.18% to 1997 to 3.36% in 2019 (Z= -273.40, p < 0.001). The absolute increase was higher among males compared to females (0.26-4.90% vs. 0.08-1.77%) and among non-Hispanic Whites (0.18-2.88%) compared to non-Hispanic Blacks (0.23-2.72%), Hispanics (0.14-2.60%), and Other races (0.19-2.97%). The epidemiologic patterns of ASD based on inpatient data are generally consistent with reports from the community-based autism surveillance system. Our findings indicate that KID and other health services data might play a complementary role in ASD surveillance.

Variation in ontogenetic trajectories of limb dimensions in humans is attributable to both climatic effects and neutral evolution

Previous studies showed that there is variation in ontogenetic trajectories of human limb dimensions and proportions. However, little is known about the evolutionary significance of this variation. This study used a global sample of modern human immature long bone measurements and a multivariate linear mixed-effects model to study 1) whether the variation in ontogenetic trajectories of limb dimensions is consistent with ecogeographic predictions and 2) the effects of different evolutionary forces on the variation in ontogenetic trajectories. We found that genetic relatedness arising from neutral (nonselective) evolution, allometric variation associated with the change in size, and directional effects from climate all contributed to the variation in ontogenetic trajectories of all major long bone dimensions in modern humans. After accounting for the effects of neutral evolution and holding other effects considered in the current study constant, extreme temperatures have weak, positive associations with diaphyseal length and breadth measurements, while mean temperature shows negative associations with diaphyseal dimensions. The association with extreme temperatures fits the expectations of ecogeographic rules, while the association with mean temperature may explain the observed among-group variation in intralimb indices. The association with climate is present throughout ontogeny, suggesting an explanation of adaptation by natural selection as the most likely cause. On the other hand, genetic relatedness among groups, as structured by neutral evolutionary factors, is an important consideration when interpreting skeletal morphology, even for nonadult individuals.

It Runs in the Family: Testing for Longitudinal Family Flynn Effects

The Flynn effect refers to increases over time in measured (particularly fluid) intelligence of approximately 3 IQ points per decade. We define the Flynn effect at the family level, using longitudinal data and two new family-level cohort definitions. Multilevel growth curve analyses of the National Longitudinal Survey of Youth 1979 data showed that children in families with later-born mothers had higher average PIAT math scores, and lower average reading comprehension scores and growth, in young and middle childhood. Children in families where the first child was born later had higher average PIAT math, reading recognition, and reading comprehension scores, as well as larger developmental growth. The latter family-level Flynn effects were of higher magnitudes than the usual individual-level Flynn effect found in previous studies. Our results, showing family level-intercept and slope Flynn effects for both maternal birthyear and first child birthyear, have implications for research aiming to explain the Flynn effect.

An age-period-cohort approach to studying long-term trends in obesity and overweight in England (1992-2019)

OBJECTIVE

This study aims to understand long-term trends in obesity and overweight in England by estimating life-course transitions as well as historical and birth cohort trends for both children and adults.

METHODS

Data on individuals aged 5 to 85 years old from the Health Survey for England were used, covering the period 1992 to 2019 and birth cohorts born between 1909 and 2013. Individual BMI values were classified as healthy weight, overweight, or obesity. Trends were compared, and an age-period-cohort model was estimated using logistic regression and categorical age, period, and cohort groups.

RESULTS

There was significant variation in age trajectories by birth cohorts for healthy weight and obesity prevalence. The odds of having obesity compared with a healthy weight increased consistently with age, increased throughout the study period (but faster between 1992 and 2001), and were higher for birth cohorts born between 1989 and 2008. The odds of having overweight showed an inverted U-shape among children, increased through adulthood, have been stable since 2012, and were considerably higher for the youngest birth cohort (2009-2013).

CONCLUSIONS

Younger generations with higher overweight prevalence coupled with increasing obesity prevalence with age suggest that obesity should remain a high priority for public health policy makers in England.

Structural racism theory, measurement, and methods: A scoping review

Introduction

Epidemiologic and public health interest in structural racism has grown dramatically, producing both increasingly sophisticated questions, methods, and findings, coupled with concerns of atheoretical and ahistorical approaches that often leave the actual production of health or disease ambiguous. This trajectory raises concerns as investigators adopt the term "structural racism" without engaging with theories and scholars with a long history in this area. This scoping review aims to build upon recent work by identifying current themes about the incorporation of structural racism into (social) epidemiologic research and practice with respect to theory, measurement, and practices and methods for trainees and public health researchers who are not already deeply grounded in this work.

Methods

This review uses methodological framework and includes peer-review articles written in English published between January 2000-August 2022.

Results

A search of Google Scholar, manual collection, and referenced lists identified a total of 235 articles; 138 met the inclusion criteria after duplicates were removed. Results were extracted by, and organized into, three broad sections: theory, construct measurement, and study practice and methods, with several themes summarized in each section.

Discussion

This review concludes with a summary of recommendations derived from our scoping review and a call to action echoing previous literature to resist an uncritical and superficial adoption of "structural racism" without attention to already existing scholarship and recommendations put forth by experts in the field.

A double-diamond retrospective on modeling change in attitudes and opinions

The five decades of results produced by analysts of the General Social Survey (GSS) have enriched our understanding of social change, but some core modeling challenges remain. This article proposes that we more fully engage in the development of targeted models of period-based attitude and opinion change, using counterfactual reasoning, as we continue to model cohort replacement. This shift is also consistent with the recent literature on age, period, and cohort analysis, which argues for attention to age varying period effects. Two outcomes are modeled to provide material for the argument: support for government spending on drug addiction and rehabilitation and the valuation of obedience as a goal for child behavioral development.

Physical activity, sleep quality and life satisfaction in adolescents: A cross-sectional survey study

Background

Physical activity, sleep is an important component of adolescents' 24-h movement behavior, and life satisfaction predicts adolescent physical and mental health. However, few studies have explored the relationship between the two variables among Chinese high school students. Consequently, this study aimed to explore the relationship between sleep quality and life satisfaction among Chinese high school students.

Methods

This cross-sectional study was conducted in October 2020 in five high schools in Xuchang City, China. High school students from senior 1 to senior 3 were asked to fill up a questionnaire of demographic characteristics and validated screen instructions for sleep quality (Pittsburgh Sleep Quality Index) and life satisfaction (Satisfaction with Life Scale). The multivariate regression model was applied to explore the association between sleep quality and life satisfaction.

Results

A total of 1127 individuals (51.1% males) participated in this survey, and the prevalence of poor sleep quality was 42.3%. The mean score on the Satisfaction with Life Scale was 16.72 ± 5.67, according to the corresponding scoring criteria, with 15-19 being generally dissatisfied. After controlling for demographic variables, the contribution of subjective sleep quality (β = - 0.181, p < 0.01), sleep duration (β = - 0.080, p < 0.01) and daytime dysfunction (β = - 0.311, p < 0.01) to life satisfaction of high school students increased to 23.2%, indicating that subjective sleep quality, sleep duration, and daytime dysfunction were 22.9% predictive of life satisfaction among high school students. And also, physical activity on schooldays and weekend days were associated with better sleep quality and higher life satisfaction (p < 0.05).

Conclusions

Among Chinese high school students, the prevalence of sleep problems was high, and the majority of students held moderate life satisfaction. Sleep quality was positively correlated with life satisfaction among Chinese high school students, with better sleep quality resulting in higher life satisfaction among students.

Changes over time in patient visits and continuity of care among graduating cohorts of family physicians in 4 Canadian provinces

BACKGROUND

Lack of patient access to family physicians in Canada is a concern. The role of recent physician graduates in this problem of supply of primary care services has not been established. We sought to establish whether career stage or graduation cohort were related to family physician practice volume and continuity of care over time.

METHODS

We conducted a retrospective cohort study of family physician practice from 1997/98 to 2017/18. We collected administrative health and physician claims data in British Columbia, Manitoba, Ontario and Nova Scotia. We included all physicians who registered with their respective provincial regulatory colleges as having a medical specialty of family practice or who had billed the provincial health insurance system for patient care as family physicians, or both. We used regression models to isolate the effects of 3-year categories of years in practice (at all career stages), time period and cohort on patient contacts and physician-level continuity of care.

RESULTS

Between 1997/98 and 2017/18, the median number of patient contacts per provider per year fell by between 515 and 1736 contacts in the 4 provinces examined. Median contacts peaked at 27-29 years in practice in all provinces, and median physician-level continuity of care increased until 30 or more years in practice. We found no association between graduation cohort and patient contacts or physician-level continuity of care.

INTERPRETATION

Recent cohorts of family physicians practise similarly to their predecessors in terms of practice volumes and continuity of care. Because family physicians of all career stages showed declining patient contacts, we suggest that system-wide solutions to recent challenges in the accessibility of primary care in Canada are needed.

Age, period and cohort effects in depression prevalence among Canadians 65+, 1994 to 2018: A multi-level analysis

BACKGROUND

The nature of the Canadian population 65+ has changed considerably over the past several decades. They comprise a larger proportion of the population, are better educated, and are wealthier than previous generations. We estimate the contributions of chronological aging, temporal periods, and birth cohort effects on the trends in the major depressive episode (MDE) prevalence among Canadian seniors from 1994/1995 to 2017/2018.

METHODS

Using data from two sets of national health surveys, the National Population Health Survey (NPHS) and the Canadian Community Health Survey (CCHS). Pooled data on 150,246 survey respondents aged 65+ from 16 repeated cross-sectional surveys are included. Hierarchical regression age-period-cohort models were used to visualize the linear and non-linear effects of age, period, and cohort trends in late-life depression.

RESULTS

We found that: the prevalence of MDE in later life fluctuated non-significantly during the study time period; the probability of developing MDE declined with increasing age from 65 to 80+ (β = -.32, p = .027). The significant quadratic birth cohort predictor showed a non-linear increasing association with the prevalence of MDE from the earlier to later-born cohorts (β = .01, p = .049). We also found that females 65+ were consistently more likely to be depressed than males 65+ (β = .47, p = .007). The significantly negative "age × female" interaction shows that age exerts a greater effect on females' probability of developing MDE than males (β = -.09, p = .011). There were no consistent significant period effects but there were peaks in prevalence around 2001, 2008, and 2012 which corresponded to some recent historical events. Our moderation analysis documents that lower levels of education significantly contributed to the higher rates of depression among cohorts born earlier in the 20th century.

CONCLUSIONS

Our findings show the presence of strong chronological age and cohort effects and weaker period effects on the prevalence of late-life depression in Canadian seniors.

Human papillomavirus vaccination uptake among childhood cancer survivors in Western New York

INTRODUCTION

The risk of human papillomavirus (HPV)-associated cancers is significantly higher among survivors of a childhood cancer compared to the general population. Despite this, their HPV vaccine uptake rates are lower. We examined factors related to HPV vaccine uptake among childhood cancer survivors from Western New York over 13 years following the introduction of HPV vaccines.

METHODS

Retrospective review of patients diagnosed with invasive or noninvasive cancerous conditions at age 9 or younger treated at Roswell Park Oishei Children's Cancer and Blood Disorder Program. We matched vaccine date information for patients aged 9-26 years between 2006 and 2020 from the New York State Immunization Information System. Demographic and cancer-related information was abstracted from electronic medical records. Cumulative vaccine uptake was assessed by Kaplan-Meier and Cox proportional hazards regression models.

RESULTS

A total of 284 patients were included in the analyses. Most were non-Hispanic/White (80.3%) and resided in a metropolitan area (81.7%). Approximately half had leukemia or lymphoma (54.9%), and most received chemotherapy. Females were more likely to initiate the HPV vaccine and did so sooner (median = 5.5 years) than males (median = 5.7 years; log-rank p = .301). Patients who were older at vaccine eligibility and males who received blood product transfusions were significantly less likely to initiate the HPV vaccine.

CONCLUSION

While rates of HPV vaccine initiation have been increasing with time among childhood cancer survivors, they remain low overall, with differences seen by treatment and diagnosis. Our findings support the need for further research to optimize HPV vaccine delivery in cancer care.

Investigating change across time in prevalence or association: the challenges of cross-study comparative research and possible solutions

Cross-study research initiatives to understand change across time are an increasingly prominent component of social and health sciences, yet they present considerable practical, analytical and conceptual challenges. First, we discuss the key challenges to comparative research as a basis for detecting societal change, as well as possible solutions. We focus on studies which investigate changes across time in outcome occurrence or the magnitude and/or direction of associations. We discuss the use and importance of such research, study inclusion, sources of bias and mitigation, and interpretation. Second, we propose a structured framework (a checklist) that is intended to provide guidance for future authors and reviewers. Third, we outline a new open-access teaching resource that offers detailed instruction and reusable analytical syntax to guide newcomers on techniques for conducting comparative analysis and data visualisation (in both R and Stata formats).

Supplementary Information

The online version contains supplementary material available at 10.1007/s44155-022-00021-1.

Beliefs about harms of cigarette smoking among Norwegian adults born from 1899 to 1969. Do variations across education, smoking status and sex mirror the decline in smoking?

BACKGROUND AND AIM

Smoking is one of the most important causes of socioeconomic disparities in morbidity and mortality. The aim of this study was to examine if beliefs about harms of smoking differed across gender, smoking status and education among Norwegian adults born between 1899 and 1969.

METHODS

Using data from a nationally representative survey of smoking habits and a multinomial logit/negative binomial two-stage hurdle model design, we examined (first hurdle) the associations between birth cohort, gender, education and smoking status and four beliefs about cigarette smoking: i) smoking is not harmful, ii) do not know if smoking is harmful, iii) any number of cigarettes per day (CPD) is harmful and iv) smoking more than a given nonzero number of CPD is harmful, and (second hurdle) the predicted number of CPD that could be smoked without causing harm (from outcome iv).

RESULTS

The probability of believing that smoking was not harmful was close to zero, regardless of birth cohort, sex, education and smoking status. The probability of not knowing if smoking was harmful decreased from around 0.7 to almost zero across cohorts. The probability of believing that smoking more than zero CPD was harmful increased from less than 0.1 to around 0.7, while the probability of believing that there is some safe level of smoking increased with cohorts born from 1900 to 1930 before declining. Respondents with primary/secondary education consistently believed smoking to be less harmful compared to respondents with tertiary education, but cohort trajectories were similar.

DISCUSSION

The similar birth cohort trajectories in beliefs about the harms of smoking do not support the idea that Norwegian adults with lower education has had qualitatively different beliefs about the harmfulness of smoking compared to those with higher education. The persistent and large socioeconomic gradient is likely a result of other factors.

The Age-Period-Cohort-Interaction Model for Describing and Investigating Inter-cohort Deviations and Intra-cohort Life-course Dynamics

Social scientists have frequently sought to understand the distinct effects of age, period, and cohort, but disaggregation of the three dimensions is difficult because cohort = period - age. We argue that this technical difficulty reflects a disconnection between how cohort effect is conceptualized and how it is modeled in the traditional age-period-cohort framework. We propose a new method, called the age-period-cohort-interaction (APC-I) model, that is qualitatively different from previous methods in that it represents Ryder's (1965) theoretical account about the conditions under which cohort differentiation may arise. This APC-I model does not require problematic statistical assumptions and the interpretation is straightforward. It quantifies inter-cohort deviations from the age and period main effects and also permits hypothesis testing about intra-cohort life-course dynamics. We demonstrate how this new model can be used to examine age, period, and cohort patterns in women's labor force participation.

Breast cancer risk predictions by birth cohort and ethnicity in a population-based screening mammography program

OBJECTIVES

To examine whether birth cohorts affect the risk of breast cancer for East Asian, First Nations, African, South Asian and Caucasian ethnicities in British Columbia (BC).

METHODS

We used Cox PH models adjusted for well-known risk factors, such as age, breast density, mammographic features on false positives, and family history, to examine risk of breast cancer among East Asian, First Nations, African and South Asian ethnicities, relative to Caucasian, across three birth cohorts.

RESULTS

There were 813,280 participants and 11,166 in situ and invasive breast cancer diagnoses. East Asians screened in BC were found to have a lower risk of breast cancer in the birth cohort born pre-1946 compared to Caucasian, but there was no statistically significant decrease for East Asians born after 1946. First Nations had an increased risk of breast cancer compared with Caucasian for all birth cohorts ranging from 1.1 to 2.0x the risk, which was statistically significant for those born after 1965. South Asians showed a statistically significant decrease in risk ranging from 0.58 to 0.81x lower compared with Caucasians for all birth cohorts.

CONCLUSION

Risk of breast cancer for South Asians living in BC was found to be lower than Caucasians for each birth cohort examined, while East Asians had a comparable risk of breast cancer, First Nations had a consistently higher risk than Caucasians.

ADVANCES IN KNOWLEDGE

When accounting for birth cohort, compared to Caucasians, South Asians have a decreased risk, First Nations have an increased risk, and East Asians have a similar risk of breast cancer.

Gender Differences in the Psychopharmacological Treatment of Forensic In-Patients With Schizophrenia

Background

In forensic psychiatry, psychopharmacological treatment plays a crucial role for patients with schizophrenia in improving their medical as well as legal prognosis. However, an increase in the number of females entering forensic treatment has yet to yield empirical research on the outcome of psychopharmacological treatment of female patients with schizophrenia in terms of efficacy and tolerability.

Aims

The aim of the present study is to elucidate pharmacological treatment strategies of women with schizophrenia in forensic psychiatry in comparison with men.

Methods

This study compares psychopharmacological treatment strategies, psychopathological features, as well as neurological and metabolic side effects of treatment between 29 female and 29 male in-patients with schizophrenia in three forensic facilities in Bavaria, Germany.

Results

Results show significant differences between genders. Poorer psychopathological and neurological features were found in the female sample, while men registered worse metabolic parameters. In terms of psychopharmacological treatment strategies, female in-patients were more often prescribed second-generation depot antipsychotics. Surprisingly, the potency of the dosages did not differ between genders. The results suggest that female forensic patients with schizophrenia have more severe and refractory diseases than their male counterparts.

Conclusion

Recommendations for gender-specific treatment strategies are derived.

Obesity Incidence in U.S. Children and Young Adults: A Pooled Analysis

INTRODUCTION

Obesity prevalence among children and adolescents has risen sharply, yet there is a limited understanding of the age-specific dynamics of obesity as there is no single nationally representative cohort following children into young adulthood. Investigators constructed a pooled data set of 5 nationally representative panels and modeled age-specific obesity incidence from childhood into young adulthood.

METHODS

This longitudinal prospective follow-up used 718,560 person-years of observation in a pooled data set of 5 high-quality nationally representative panels-National Longitudinal Survey of Youth 1979 and 1997, National Longitudinal Study of Adolescent Health, and Early Childhood Longitudinal Study-Kindergarten cohorts of 1998 and 2011-constructed by the authors, covering 1980-2016. Differences in obesity incidence across birth cohorts and disparities in obesity incidence by sex and race/ethnicity (non-Hispanic Black, Hispanic, and non-Hispanic White) were tested in multivariate models. Data were analyzed from September 2018 to October 2021.

RESULTS

Obesity incidence increased by approximately 6% for each 1 year of age (hazard ratio=1.06, 95% CI=1.05, 1.07); however, incidence was nonlinear, exhibiting an inverted "U"-shaped pattern before 15 years of age and then rising from adolescence through 30 years. Obesity incidence more than doubled between the cohorts born in 1957-1965 and those born in 1974-1985 during adolescence. There was no significant change among those born in 1991-1994 and 2003-2006 up to age 15 years. Compared with non-Hispanic White children, non-Hispanic Black and Hispanic children had higher obesity incidence in all study cohorts. The magnitude of these disparities on the relative scale remained stable throughout the study period.

CONCLUSIONS

Although many children become obese before the age of 10, obesity incidence rises from about 15 years into early adulthood, suggesting that interventions are required at multiple developmental stages.

The Financial Correlates of Midlife Obesity

INTRODUCTION

This study explored the associations between midlife obesity and an array of common financial stressors related to wealth loss, debt, and bankruptcy.

METHODS

The analysis was conducted in 2022 with data from the National Longitudinal Survey of Youth 1979. The final sample included 36,122 observations on 8,059 respondents as they aged from ages 31‒39 years in 1996 to ages 51‒59 in 2016. Associations between obesity and financial stressors were estimated with logistic regression models adjusting for a comprehensive set of relevant control variables.

RESULTS

The analysis found significant relationships between obesity and multiple types of financial stressors, including property debt, unsecured debt, and bankruptcy. Property debt and unsecured debt increased the odds of obesity by 29% and 20%, respectively, and bankruptcy increased the odds of obesity by 43%. Average Marginal Effects (AMEs) in combination with model fit statistics confirmed that these stressors-unsecured debt, property debt, and bankruptcy-were important financial correlates of midlife obesity among the National Longitudinal Survey of Youth 1979 cohort.

CONCLUSIONS

The financial correlates of obesity included multiple financial stressors, but the magnitude of associations varied substantially across types of financial stressors. Results suggest that future interventions aimed at reducing obesity disparities should target populations with high levels of debt and bankruptcy.

Understanding long-term trends in smoking in England, 1972-2019: an age-period-cohort approach

BACKGROUND AND AIMS

Smoking prevalence has been falling in England for more than 50 years, but remains a prevalent and major public health problem. This study used an age-period-cohort (APC) approach to measure lifecycle, historical and generational patterns of individual smoking behaviour.

DESIGN

APC analysis of repeated cross-sectional smoking prevalence data obtained from three nationally representative surveys.

SETTING

England (1972-2019).

PARTICIPANTS

Individuals aged 18-90 years.

MEASUREMENTS

We studied relative odds of current smoking in relation to age in single years from 18 to 90, 24 groups of 2-year survey periods (1972-73 to 2018-19) and 20 groups of 5-year birth cohorts (1907-11 to 1997-2001). Age and period rates were studied for two groups of birth cohorts: those aged 18-25 years and those aged over 25 years.

FINDINGS

Relative to age 18, the odds of current smoking increased with age until approximately age 25 [odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.41-1.56] and then decreased progressively to age 90 (OR = 0.06, 95% CI = 0.04-0.08). They also decreased almost linearly with period relative to 1972-73 (for 2018-19: OR = 0.30, 95% CI = 0.26-0.34) and with birth cohort relative to 1902-06, with the largest decreased observed for birth cohort 1992-96 (OR = 0.44, 95% CI = 0.35-0.46) and 1997-2001 (OR = 0.35, 95% CI = 0.74-0.88). Smoking declined in the 18-25 age group by an average of 7% over successive 2-year periods and by an average of 5% in those aged over 25.

CONCLUSIONS

Smoking in England appears to have declined over recent decades mainly as a result of reduced smoking uptake before age 25, and to a lesser extent to smoking cessation after age 25.

The relationship between sleep and weight change among women diagnosed with breast cancer participating in the Women's Health Initiative

PURPOSE

Short and long sleep duration and poor sleep quality are risk factors for weight gain and cancer mortality. The purpose of this study is to investigate the relationship between sleep and weight change among postmenopausal breast cancer survivors.

METHODS

Women participating in the Women's Health Initiative who were diagnosed with incident breast cancer between year one and year three were included. Self-reported sleep duration was categorized as ≤ 5 h (short), 6 h, 7-8 h (optimal), and ≥ 9 h (long). Self-reported sleep quality was categorized as poor, average, and above average. Post-diagnosis weight change was the difference of weight closest to, but preceding diagnosis, and year 3 weight. We used linear regression to evaluate sleep duration and sleep quality associations with post-diagnosis weight change adjusted for potential confounders.

RESULTS

Among 1156 participants, 63% were weight stable after diagnosis; average weight gain post cancer diagnosis was 3.2 kg. Six percent of women reported sleeping ≤ 5 h, 26% reported 6 h, 64% reported 7-8 h, and 4% reported ≥ 9 h. There were no differences in adjusted estimates of weight change among participants with short duration (0.37 kg; 95% CI - 0.88, 1.63), or long duration (- 0.56 kg; 95% CI - 2.03, 0.90) compared to optimal duration, nor was there a difference among poor quality (- 0.51 kg; 95% CI - 1.42, 0.41) compared to above average quality.

CONCLUSION

Among postmenopausal breast cancer survivors, sleep duration and quality were not associated with weight change after breast cancer diagnosis. Future studies should consider capturing change in adiposity and to expand beyond self-reported sleep.

Age, Period, and Cohort Effects of Internalizing Symptoms Among US Students and the Influence of Self-Reported Frequency of Attaining 7 or More Hours of Sleep: Results From the Monitoring the Future Survey 1991-2019

Adolescent internalizing symptoms have increased since 2010, whereas adequate sleep has declined for several decades. It remains unclear how self-reported sleep attainment has affected internalizing-symptoms trends. Using 1991-2019 data from the Monitoring the Future Study (n ~ 390,000), we estimated age-period-cohort effects in adolescent internalizing symptoms (e.g., loneliness, self-esteem, self-derogation, depressive affect) and the association with yearly prevalence of a survey-assessed, self-reported measure of attaining ≥7 hours of sleep most nights. We focused our main analysis on loneliness and used median odds ratios to measure variance in loneliness associated with period differences. We observed limited signals for cohort effects and modeled only period effects. The feeling of loneliness increased by 0.83% per year; adolescents in 2019 had 0.68 (95% CI: 0.49, 0.87) increased log odds of loneliness compared with the mean, which was consistent by race/ethnicity and parental education. Girls experienced steeper increases in loneliness than boys (P < 0.0001). The period-effect median odds ratio for loneliness was 1.16 (variance = 0.09; 95% CI: 0.06, 0.17) before adjustment for self-reported frequency of getting ≥7 hours sleep versus 1.07 (variance = 0.02; 95% CI: 0.01, 0.03) after adjustment. Adolescents across cohorts are experiencing worsening internalizing symptoms. Self-reported frequency of <7 hours sleep partially explains increases in loneliness, indicating the need for feasibility trials to study the effect of increasing sleep attainment on internalizing symptoms.

The Age–Period–Cohort Problem in Hedonic House Prices Models

The age–period–cohort problem has been studied for decades but without resolution. There have been many suggested solutions to make the three effects estimable, but these solutions mostly exploit non-linear specifications. Yet, these approaches may suffer from misspecification or omitted variable bias. This paper is a practical-oriented study with an aim to empirically disentangle age–period–cohort effects by providing external information on the actual depreciation of housing structure rather than taking age as a proxy. It is based on appraisals of the improvement values of properties in New Zealand to estimate the age-depreciation effect. This research method provides a novel means of solving the identification problem of the age, period, and cohort trilemma. Based on about half a million housing transactions from 1990 to 2019 in the Auckland Region of New Zealand, the results show that traditional hedonic prices models using age and time dummy variables can result, ceteris paribus, in unreasonable positive depreciation rates. The use of the improvement values model can help improve the accuracy of home value assessment and reduce estimation biases. This method also has important practical implications for property valuations.

Strategies Associated with Retaining Participants in the Longitudinal National Alzheimer's Coordinating Center Uniform Data Set Study

BACKGROUND

Best approaches for retaining research participants in Alzheimer's disease cohort studies are understudied.

OBJECTIVE

Using data from the National Alzheimer's Coordinating Center Uniform Data Set, we evaluated the associations of unique strategies with participant retention across Alzheimer's Disease Research Centers and explored potential effect modification by race, ethnicity and diagnostic group.

METHODS

We examined retention at the first follow-up visit among participants enrolled during 2015-2017. Structured surveys ascertained 95 retention tactics among 12 strategies. Strategy-specific summary scores were created based on the number of implemented tactics for each strategy and grouped into tertiles. Generalized estimating equations were constructed to evaluate associations between strategy scores and the odds of retention, controlling for age, sex, education, study partner type, marital status, visit length, battery length, diagnostic group, race and ethnicity. Separate models were stratified by race, ethnicity and diagnostic group. Effect modification was formally tested with interaction terms.

RESULTS

Among 5,715 total participants enrolled, 4,515 were Non-Hispanic White (79%), 335 were Hispanic/Latino (6%), 651 were Non-Hispanic Black (11%), and 214 were Non-Hispanic Asian (4%). Compared to the lowest tertile of scores, the highest tertile of scores involving improvement in study personnel and communication of study requirements and details were associated with 61% higher odds of retention in fully adjusted models (adjusted Odds Ratios [aOR] = 1.61, 95% Confidence Interval [CI] = 1.05-2.47 and aOR = 1.55, 95% CI = 1.03-2.35, respectively). We did not find evidence for effect modification.

CONCLUSION

In the setting of limited resources, specific retention strategies may be more valuable than others.

Age, Period, and Cohort Effects in Alcohol Use in the United States in the 20th and 21st Centuries: Implications for the Coming Decades

This article is part of a Festschrift commemorating the 50th anniversary of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Established in 1970, first as part of the National Institute of Mental Health and later as an independent institute of the National Institutes of Health, NIAAA today is the world's largest funding agency for alcohol research. In addition to its own intramural research program, NIAAA supports the entire spectrum of innovative basic, translational, and clinical research to advance the diagnosis, prevention, and treatment of alcohol use disorder and alcohol-related problems. To celebrate the anniversary, NIAAA hosted a 2-day symposium, "Alcohol Across the Lifespan: 50 Years of Evidence-Based Diagnosis, Prevention, and Treatment Research," devoted to key topics within the field of alcohol research. This article is based on Dr. Keyes' presentation at the event. NIAAA Director George F. Koob, Ph.D., serves as editor of the Festschrift.

Subcortical volumes across the lifespan: Data from 18,605 healthy individuals aged 3-90 years

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to examine age-related trajectories inferred from cross-sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3-90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter-individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age-related morphometric patterns.

Birth cohort differences in height, weight and BMI among Indian women aged 15-30 years: analyses based on three cross-sectional surveys

OBJECTIVE

To explore long-term trends in height, weight and BMI across birth cohorts among Indian women aged 15-30 years.

DESIGN

Nationally representative cross-sectional surveys.

SETTING

Data from three National Family Health Surveys were conducted in 1998-1999, 2005-2006 and 2015-2016. Height and weight were modelled jointly, employing a multivariate regression model with age and birth cohorts as explanatory variables. The largest birth cohort (born 1988-1992) was the reference cohort. Stratified analyses by place of residence and by marital status and dichotomised parity were also performed.

PARTICIPANTS

437 753 non-pregnant women aged 15-30 years.

RESULTS

The rate of increase in height, weight and BMI differed across birth cohorts. The rate of increase was much lower for height than weight, which was reflected in an increasing trend in BMI across all birth cohorts. In the stratified analyses, increase in height was found to be similar across urban and rural areas. Rural women born in the latest birth cohort (1998-2001) were lighter, whereas urban women were heavier compared to the reference cohort. A relatively larger increase in regression coefficients was observed among women born between 1978 and 1982 compared to women born between 1973 and 1977 when considering unmarried and nulliparous ever-married women and, one cohort later (1983-1987 v. 1978-1982), among parous ever-married women.

CONCLUSION

As the rate of increase was much larger for weight than for height, increasing trends in BMI were observed across the birth cohorts. Thus, cohort effects show an important contributory role in explaining increasing trends in BMI among young Indian women.

Role of Firearm Ownership on 2001-2016 Trends in U.S. Firearm Suicide Rates

INTRODUCTION

In the U.S., state-level household firearm ownership is strongly associated with firearm suicide mortality rates. Whether the recent increases in firearm suicide are explained by state-level household firearm ownership rates and trends remains unknown.

METHODS

Mortality data from the U.S. National Vital Statistics System and an estimate of state-level household firearm ownership rate were used to conduct hierarchical age-period-cohort (random-effects) modeling of firearm suicide mortality between 2001 and 2016. Models were adjusted for individual-level race and sex and for state-level poverty rate, unemployment rate, median household income in U.S. dollars, population density, and elevation.

RESULTS

Between 2001 and 2016, the crude national firearm suicide mortality rate increased from 6.8 to 8.0 per 100,000, and household firearm ownership rate remained relatively stable, at around 40%. Both variables were markedly heterogeneous and correlated at the state level. Age-period-cohort models revealed period effects (affecting people across ages) and cohort effects (affecting specific birth cohorts) underlying the recent increases in firearm suicide. Individuals born after 2000 had higher firearm suicide rates than most cohorts born before. A 2001-2006 decreasing period effect was followed, after 2009, by an increasing period effect that peaked in 2015. State-level household firearm ownership rates and trends did not explain cohort effects and only minimally explained period effects.

CONCLUSIONS

State-level firearm ownership rates largely explain the state-level differences in firearm suicide but only marginally explain recent increases in firearm suicide. Although firearms in the home increase firearm suicide risk, the recent national rise in firearm suicide might be the result of broader, more distal causes of suicide risk.

Adverse generational changes in obesity development converge at midlife without increased cardiometabolic risk

OBJECTIVE

Obesity is becoming a global public health problem, but it is unclear how it impacts different generations over the life course. Here, a descriptive analysis of the age-related changes in anthropometric measures and related cardiometabolic risk factors across different generations was performed.

METHODS

The development of anthropometric measures and related cardiometabolic risk factors was studied during 26 years of follow-up in the Doetinchem Cohort Study (N = 6,314 at baseline). All analyses were stratified by sex and generation, i.e., 10-year age groups (20-29, 30-39, 40-49, and 50-59 years) at baseline. Generalized estimating equations were used to test for generational differences.

RESULTS

Weight, BMI, waist circumference, and prevalence of overweight and obesity were higher, in general, in the younger generations during the first 10 to 15 years of follow-up. From age 50 to 59 years onward, these measures converged in all generations of men and women. Among cardiometabolic risk factors, only type 2 diabetes showed an unfavorable shift between the two oldest generations of men.

CONCLUSIONS

It was observed that, compared with the older generations, the younger generations had obesity at an earlier age but did not reach higher levels at midlife and beyond. This increased exposure to obesity was not (yet) associated with increased prevalence of cardiometabolic risk factors.

The Health Status Transition and Medical Expenditure Evaluation of Elderly Population in China

(1) Background: Because of the rapid expansion of the aging population in China, their health status transition and future medical expenditure have received increasing attention. This paper analyzes the health transition of the elderly and how their health transition impacts medical expenditures. At the same time, feasible policy suggestions are provided to respond to the rising medical expenditure and the demand for social care. (2) Methods: The data were obtained from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2015 and analyzed using the Markov model and the Two-Part model (TPM) to forecast the size of the elderly population and their medical expenditures for the period 2020-2060. (3) Results: The study indicates that: (1) for the elderly with a mild disability, the probability of their health improvement is high; in contrast, for the elderly with a moderate or severe disability, their health deterioration is almost certain; (2) the frequency of the diagnosis and treatments of the elderly is closely related to their health status and medical expenditure; alternatively, as the health status deteriorates, the intensity of the elderly individuals' acceptance of their diagnosis and treatment increases, and so does the medical expense; (3) the population of the elderly with mild and moderate disability demonstrates an inverted "U"-shape, which reaches a peak around 2048, whereas the elderly with severe disability show linear growth, being the target group for health care; (4) with the population increase of the elderly who have severe disability, the medical expenditure increases significantly and poses a huge threat to medical service supply. Conclusions: It is necessary to provide classified and targeted health care according to the health status of the elderly. In addition, improving the level of medical insurance, establishing a mechanism for sharing medical expenditure, and adjusting the basic demographic structure are all important policy choices.

Physical Performance in Older Cohorts: A Comparison of 81-Year-Old Swedish Men and Women Born Twelve Years Apart-Results from the Swedish Study "Good Aging in Skåne"

Materials and Methods

Birth cohorts of both sexes drawn from the Swedish study “Good Aging in Skåne” for the years 1920–22 and 1932–34 were compared. Walking, the step test, the chair stand test, and the handgrip strength test were used as proxies for the physical performance. The results were adjusted for lifestyle habits and common chronic geriatric diseases.

Results

Both men and women in the later-born cohort walked more quickly and completed the chair stand test faster, and women were also quicker in the step test. No significant differences were found in the grip test, in either the male or female cohorts. Discussion. Normative reference values for physical tests of subjects of different ages can be misleading unless cohort effects are considered. Furthermore, age-related trajectories can also be misinterpreted if cohort effects are neglected which, in the longer perspective, could affect health care planning.

Conclusion

Birth cohort effects should be considered when comparing walking speed, number of steps, chair stands, and the step test, in men and women of older age.

Predictors of glycosylated haemoglobin A1C trend among type 2 diabetes patients in a multi-ethnic country

Good control of glycosylated haemoglobin A1C in diabetes patients prevents cardiovascular complications. We aim to describe the A1C trend and determine the predictors of the trend among type 2 diabetes patients in Malaysia. Longitudinal data in the National Diabetes Registry from 2013 to 2017 were analysed using linear mixed-effects modelling. Among 17,592 patients, 56.3% were females, 64.9% Malays, and the baseline mean age was 59.1 years. The U-shaped A1C trend changed marginally from 7.89% in 2013 to 8.07% in 2017. The A1C excess of 1.07% as reported in 2017 represented about 22% higher risk of diabetes-related death, myocardial infarction, and stroke, which are potentially preventable. The predictors for higher baseline A1C were non-Chinese ethnicity, younger age groups, longer diabetes duration, patients on insulin treatment, polypharmacy use, patients without hypertension, and patients who were not on antihypertensive agents. Younger age groups predicted a linear increase in the A1C trend, whereas patients on insulin treatment predicted a linear decrease in the A1C trend. Specifically, the younger adults and patients of Indian and Malay ethnicities had the poorest A1C trends. Targeted interventions should be directed at these high-risk groups to improve their A1C control.

The Intersection Between Adverse Childhood Experiences and Environmental Tobacco Smoke in U.S. Households With Children

INTRODUCTION

Environmental tobacco smoke (ETS) is a potent risk factor for secondhand smoke (SHS) exposure. Research reveals, moreover, that children who are exposed to SHS are at an increased risk of disease and premature mortality. Limited research, however, has examined whether households with children experiencing accumulating adverse childhood experiences (ACEs) are also more likely to be characterized by ETS-particularly in the form of family members smoking inside the housing unit.

AIMS AND METHODS

The current study employs a nationally representative sample of 102 341 households with children from the three most recent cohorts of National Survey of Children's Health. Both multinomial logistic regression and a strategic comparison approach are used to examine the association between ACEs and ETS categories.

RESULTS

A large majority of households characterized by ETS report one or more ACEs, while households without ETS are largely void of ACEs. Findings indicate that this association is not merely a function of general family member smoking, as ACEs are strongly and uniquely associated with family smoking inside the housing unit-above and beyond family members smoking more generally.

CONCLUSIONS

Households exhibiting an accumulation of ACEs may benefit from interventions providing resources and education supporting smoke-free home environments. Such families may also be screened and referred through existing family and parenting programs administered in the home environment (eg, home visiting).

IMPLICATIONS

Public health initiatives designed to mitigate child adversities from early life stages may help reduce ETS in housing units-thereby diminishing the risk of secondhand smoke (SHS) exposure among children.

A century of sexual abuse victimisation: A birth cohort analysis

This study examined changes in the reported prevalence of adult and child sexual abuse over the last century and explored how changes in social and political circumstances may have affected rates. Data from two population-based face-to-face surveys conducted in New Zealand (samples of 2855 women in 2003 and 1464 women in 2019) were used to produce birth cohort prevalence estimates of three forms of sexual abuse including by an intimate partner (lifetime and 12-month), by non-partners, and child sexual abuse. A timeline of major population influences that might be associated with violence occurrence was developed. There were no changes in reported lifetime intimate partner sexual abuse prevalence estimates found over the past century. The most recent birth cohort reported the lowest rates of 12-month prevalence estimates for intimate partner sexual abuse, lifetime rates of non-partner sexual abuse, and also suggest lower reported rates of child sexual abuse. Macro-social events including feminist movements, changes in legislation, and an increase in public awareness might have contributed to women's awareness about the non-acceptability of violent behaviour, and their ability to leave relationships after violence has occurred. This may have contributed to the small recent decreases in reported 12-month rate of sexual IPV and CSA, as women's ability to leave relationships may be protective for their children. The recent decrease in reported non-partner sexual violence may also be attributed to women's greater awareness of, and agency to avoid sexual abuse. The lack of change for the lifetime prevalence of sexual IPV over the past century highlights the need for ongoing prevention efforts. While recent reductions in reported rates of child and adult sexual abuse are encouraging, even reduced rates are high and warrant sustained implementation of prevention policies and programs.

Recent incidence trend of elderly patients with glioblastoma in the United States, 2000-2017

Background

The incidence of glioblastoma increases significantly with age. With the growing and aging population, there is a lack of comprehensive analysis of recent glioblastoma incidence trend in the United States. This study aims to provide in-depth description of the patterns of incidence trends and to examine the age-period-cohort effects to the trends of glioblastoma specific to elderly patients.

Methods

The incidence rates were age-adjusted and reported per 100,000 population. We calculated the annual percent change (APC) in incidence using the Joinpoint Regression Program and conducted an age-period-cohort analysis of elderly glioblastoma reported between 2000 and 2017 to the Surveillance Epidemiology and End Results (SEER) 18 registry database.

Results

The overall incidence rate of elderly patients with glioblastoma was 13.16 per 100,000 (95% CI, 12.99–13.32) from 2000 to 2017. Non-Hispanic whites (20,406, 83.6%) made up the majority. The incidence rate of male was about 1.62 times that of female. The trend of incidence remained stable and there was a non-significant increasing tendency for all elderly patients (APC 0.3, 95% CI, − 0.1 to 0.7, p = 0.111). There was a significantly increasing incidence trend for non-Hispanic white (APC 0.6, 95% CI, 0.2 to 1.1, p = 0.013), supratentorial location (APC 0.7, 95% CI, 0.2 to 1.3, p = 0.016), tumor size < 4 cm (APC 2.5, 95% CI, 1.4 to 3.6, p < 0.001), and a significantly decreasing trend for overlapping/NOS location (APC -0.9, 95% CI, − 1.6 to − 0.2, p = 0.012), and unknown tumor size (APC -4.9, 95% CI, − 6.6 to − 3.3, p < 0.001). The age-period-cohort analysis showed the effect of age on incidence trends (p< 0.001, Wald test), while did not indicate the period and cohort effects of the incidence trends of glioblastoma (p = 0.063 and p =0.536, respectively, Wald test).

Conclusion

The overall incidence of glioblastoma in the elderly population remained stable between 2000 and 2017. Period and cohort effects were not evident in the trend of glioblastoma incidence. Future population-based studies exploring the difference in the trend of glioblastoma incidence by specific molecular subgroups are warranted to further our understanding of the etiology of glioblastoma.