Positive affect during adolescence and health and well-being in adulthood: An outcome-wide longitudinal approach.

BACKGROUND: Several intergovernmental organizations, including the World Health Organization and United Nations, are urging countries to use well-being indicators for policymaking. This trend, coupled with increasing recognition that positive affect is beneficial for health/well-being, opens new avenues for intervening on positive affect to improve outcomes. However, it remains unclear if positive affect in adolescence shapes health/well-being in adulthood. We examined if increases in positive affect during adolescence were associated with better health/well-being in adulthood across 41 outcomes. METHODS AND FINDINGS: We conducted a longitudinal cohort study using data from Add Health-a prospective and nationally representative cohort of community-dwelling U.S. adolescents. Using regression models, we evaluated if increases in positive affect over 1 year (between Wave I; 1994 to 1995 and Wave II; 1995 to 1996) were associated with better health/well-being 11.37 years later (in Wave IV; 2008; N = 11,040) or 20.64 years later (in Wave V; 2016 to 2018; N = 9,003). Participants were aged 15.28 years at study onset, and aged 28.17 or 37.20 years-during the final assessment. Participants with the highest (versus lowest) positive affect had better outcomes on 3 (of 13) physical health outcomes (e.g., higher cognition (ß = 0·12, 95% CI = 0·05, 0·19, p = 0.002)), 3 (of 9) health behavior outcomes (e.g., lower physical inactivity (RR = 0·80, CI = 0·66, 0·98, p = 0.029)), 6 (of 7) mental health outcomes (e.g., lower anxiety (RR = 0·81, CI = 0·71, 0·93, p = 0.003)), 2 (of 3) psychological well-being (e.g., higher optimism (ß = 0·20, 95% CI = 0·12, 0·28, p < 0.001)), 4 (of 7) social outcomes (e.g., lower loneliness (ß = -0·09, 95% CI = -0·16, -0·02, p = 0.015)), and 1 (of 2) civic/prosocial outcomes (e.g., more voting (RR = 1·25, 95% CI = 1·16, 1·36, p < 0.001)). Study limitations include potential unmeasured confounding and reverse causality. CONCLUSIONS: Enhanced positive affect during adolescence is linked with a range of improved health/well-being outcomes in adulthood. These findings suggest the promise of testing scalable positive affect interventions and policies to more definitively assess their impact on outcomes.

Harnessing causal forests for epidemiologic research: key considerations.

Assessing heterogeneous treatment effects (HTEs) is an essential task in epidemiology. The recent integration of machine learning into causal inference has provided a new, flexible tool for evaluating complex HTEs: causal forest. In a recent paper, Jawadekar et al (Am J Epidemiol. 2023;192(7):1155-1165) introduced this innovative approach and offered practical guidelines for applied users. Building on their work, this commentary provides additional insights and guidance to promote the understanding and application of causal forest in epidemiologic research. We start with conceptual clarifications, differentiating between honesty and cross-fitting, and exploring the interpretation of estimated conditional average treatment effects. We then delve into practical considerations not addressed by Jawadekar et al, including motivations for estimating HTEs, calibration approaches, and ways to leverage causal forest output with examples from simulated data. We conclude by outlining challenges to consider for future advancements and applications of causal forest in epidemiologic research.

Do Adverse Childhood Experiences Modify the Association Between Disaster-Related Trauma and Cognitive Disability?

Identifying subpopulations that are particularly vulnerable to long-term adverse health consequences of disaster-related trauma is needed. We examined whether adverse childhood experiences (ACEs) potentiate the association between disaster-related trauma and subsequent cognitive disability among older adult disaster survivors. Data were from a prospective cohort study of older adults who survived the 2011 Great East Japan Earthquake. The baseline survey pre-dated the disaster by 7 months. We included participants who completed follow-up surveys (2013 and 2016) and did not have a cognitive disability before the disaster (n = 602). Disaster-related traumas (i.e., home loss, loss of friends or pets) and ACEs were retrospectively assessed in 2013. Cognitive disability levels in 2016 were objectively assessed. After adjusting for pre-disaster characteristics using a machine learning-based estimation approach, home loss (0.19, 95% confidence interval (CI): 0.09, 0.28) was, on average, associated with greater cognitive disability. Among individuals with ACEs, home loss was associated with even higher cognitive disability levels (0.64, 95% CI: 0.24, 1.03). Losses of friends (0.18, 95% CI: 0.05, 0.32) and pets (0.13, 95% CI: 0.02, 0.25) were associated with higher cognitive disability levels only among those with ACEs. Our findings suggest that individuals with a history of ACEs may be particularly vulnerable to adverse health consequences related to disasters.

The silent epidemic of loneliness: identifying the antecedents of loneliness using a lagged exposure-wide approach.

BACKGROUND: A large and accumulating body of evidence shows that loneliness is detrimental for various health and well-being outcomes. However, less is known about potentially modifiable factors that lead to decreased loneliness. METHODS: We used data from the Health and Retirement Study to prospectively evaluate a wide array of candidate predictors of subsequent loneliness. Importantly, we examined if changes in 69 physical-, behavioral-, and psychosocial-health factors (from t0;2006/2008 to t1;2010/2012) were associated with subsequent loneliness 4 years later (t2;2014/2016). RESULTS: Adjusting for a large range of covariates, changes in certain health behaviors (e.g. increased physical activity), physical health factors (e.g. fewer functioning limitations), psychological factors (e.g. increased purpose in life, decreased depression), and social factors (e.g. greater number of close friends) were associated with less subsequent loneliness. CONCLUSIONS: Our findings suggest that subjective ratings of physical and psychological health and perceived social environment (e.g. chronic pain, self-rated health, purpose in life, anxiety, neighborhood cohesion) are more strongly associated with subsequent loneliness. Yet, objective ratings (e.g. specific chronic health conditions, living status) show less evidence of associations with subsequent loneliness. The current study identified potentially modifiable predictors of subsequent loneliness that may be important targets for interventions aimed at reducing loneliness.

Association of disaster-related damage with inflammatory diet among older survivors of the Great East Japan Earthquake and Tsunami.

Traumatic experiences from disasters have enduring effects on health, both directly and indirectly by influencing health behaviours. Among potential pathways, the impact of disaster-related trauma on dietary patterns has been understudied. This study investigated the relationship between disaster-related trauma and dietary inflammatory index (DII®), and how these relationships differed by gender and whether they prepare meal by themselves or not among older survivors of the 2011 Great East Japan Earthquake and Tsunami (n 1375). Dietary data were collected in 2020 using a brief-type self-administered diet history questionnaire, from which we derived a dietary inflammatory index (DII®) based on twenty-six food/nutrient items, where higher scores indicate pro-inflammatory (i.e. unhealthy) diet. We found that the experience of housing damage due to the earthquake and tsunami was associated with slightly higher DII scores (coef. = 0·38, 95 % CI -0·05, 0·81). Specifically, women who cooked by themselves tended to have higher DII when they experienced housing damage (coef. = 1·33, 95 %CI -0·63, 3·28). On the other hand, loss of friends was associated with a lower DII score (coef. = -0·28, 95 % CI -0·54, -0·01). These findings highlight the importance of providing support to groups who are at increased risk of deterioration in dietary quality in the aftermath of disasters.

Uncovering Heterogeneous Associations Between Disaster-Related Trauma and Subsequent Functional Limitations: A Machine-Learning Approach.

This study examined heterogeneity in the association between disaster-related home loss and functional limitations of older adults, and identified characteristics of vulnerable subpopulations. Data were from a prospective cohort study of Japanese older survivors of the 2011 Japan Earthquake. Complete home loss was objectively assessed. Outcomes in 2013 (n = 3,350) and 2016 (n = 2,664) included certified physical disability levels, self-reported activities of daily living, and instrumental activities of daily living. We estimated population average associations between home loss and functional limitations via targeted maximum likelihood estimation with SuperLearning and its heterogeneity via the generalized random forest algorithm. We adjusted for 55 characteristics of survivors from the baseline survey conducted 7 months before the disaster. While home loss was consistently associated with increased functional limitations on average, there was evidence of effect heterogeneity for all outcomes. Comparing the most and least vulnerable groups, the most vulnerable group tended to be older, not married, living alone, and not working, with preexisting health problems before the disaster. Individuals who were less educated but had higher income also appeared vulnerable for some outcomes. Our inductive approach for effect heterogeneity using machine learning algorithm uncovered large and complex heterogeneity in postdisaster functional limitations among Japanese older survivors.

Associations of online religious participation during COVID-19 lockdown with subsequent health and well-being among UK adults.

BACKGROUND: In-person religious service attendance has been linked to favorable health and well-being outcomes. However, little research has examined whether online religious participation improves these outcomes, especially when in-person attendance is suspended. METHODS: Using longitudinal data of 8951 UK adults, this study prospectively examined the association between frequency of online religious participation during the stringent lockdown in the UK (23 March -13 May 2020) and 21 indicators of psychological well-being, social well-being, pro-social/altruistic behaviors, psychological distress, and health behaviors. All analyses adjusted for baseline socio-demographic characteristics, pre-pandemic in-person religious service attendance, and prior values of the outcome variables whenever data were available. Bonferroni correction was used to correct for multiple testing. RESULTS: Individuals with online religious participation of ≥1/week (v. those with no participation at all) during the lockdown had a lower prevalence of thoughts of self-harm in week 20 (odds ratio 0.24; 95% CI 0.09-0.62). Online religious participation of <1/week (v. no participation) was associated with higher life satisfaction (standardized ß = 0.25; 0.11-0.39) and happiness (standardized ß = 0.25; 0.08-0.42). However, there was little evidence for the associations between online religious participation and all other outcomes (e.g. depressive symptoms and anxiety). CONCLUSIONS: There was evidence that online religious participation during the lockdown was associated with some subsequent health and well-being outcomes. Future studies should examine mechanisms underlying the inconsistent results for online v. in-person religious service attendance and also use data from non-pandemic situations.

Who Benefits From Helping? Moderators of the Association Between Informal Helping and Mortality.

BACKGROUND: While informal helping has been linked to a reduced risk of mortality, it remains unclear if this association persists across different levels of key social structural moderators. PURPOSE: To examine whether the longitudinal association between informal helping and all-cause mortality differs by specific social structural moderators (including age, gender, race/ethnicity, wealth, income, and education) in a large, prospective, national, and diverse sample of older U.S. adults. METHODS: We analyzed data from the Health and Retirement Study, a national sample of U.S. adults aged >50 (N = 9,662). Using multivariable Poisson regression, we assessed effect modification by six social structural moderators (age, gender, race/ethnicity, wealth, income, and education) for the informal helping (2006/2008) to mortality (2010-2016/2012-2018) association on the additive and multiplicative scales. RESULTS: Participants who reported ≥100 hr/year of informal helping (vs. 0 hr/year), had a lower mortality risk. Those who engaged in 1-49 hr/year most consistently displayed lower mortality risk across moderators, while those who engaged in 50-99 and ≥100 hr/year only showed decreased mortality risk across some moderators. When formally testing effect modification, there was evidence that the informal helping-mortality associations were stronger among women and the wealthiest. CONCLUSIONS: Informal helping is associated with decreased mortality. Yet, there appear to be key differences in who benefits from higher amounts of informal helping across social structural moderators. Further research is needed to evaluate how the associations between informal helping and health and well-being are patterned across key social structural moderators.

Informal helping has been associated with a decreased mortality risk, but it remains unclear if this association persists across different levels of key social structural moderators. We examined whether the longitudinal association between informal helping and all-cause mortality differs across age, gender, race/ethnicity, wealth, income, and education, in a large sample of older U.S. adults from the Health and Retirement Study (N = 9,662). Participants who reported ≥100 hr/year of informal helping (vs. 0 hr/year), had a lower mortality risk. Those who engaged in 1­49 hr/year most consistently displayed lower mortality risk across moderators, while those who engaged in 50­99 and ≥100 hr/year only showed decreased mortality risk across some moderators. There was evidence that the informal helping­mortality associations were stronger among women and the wealthiest when testing effect modification. While informal helping was associated with decreased mortality, there appear to be key differences in who benefits from higher amounts of informal helping across social structural moderators. Further research is needed to evaluate how the associations between informal helping and health and well-being differ across important social structural factors.

Purpose in life and 8-year mortality by gender and race/ethnicity among older adults in the U.S.

We examined the associations between a sense of purpose and all-cause mortality by gender and race/ethnicity groups. Data were from the Health and Retirement Study, a nationally representative cohort study of U.S. adults aged >50 (n = 13,159). Sense of purpose was self-reported at baseline (2006/2008), and risk of all-cause mortality was assessed over an 8-year follow-up period. We also formally tested for potential effect modification by gender and race/ethnicity. We observed the associations between higher purpose and lower all-cause mortality risk across all gender and race/ethnicity groups. There was modest evidence that the highest level of purpose (versus lowest quartile) was associated with even lower risk of all-cause mortality among women (risk ratio = 0.66, 95% confidence interval: 0.56, 0.77) compared to men (risk ratio = 0.80, 95% confidence interval: 0.69, 0.93; p-value for multiplicative effect modification =0.07). However, we observed no evidence of effect modification by race/ethnicity. Having a higher sense of purpose appears protective against all-cause mortality regardless of gender and race/ethnicity. Purpose, a potentially modifiable factor, might be a health asset across diverse populations.

Early childhood adversity and late-life depressive symptoms: unpacking mediation and interaction by adult socioeconomic status.

PURPOSE: Adverse childhood experiences (ACEs) have been linked to diminished health achievement across the life course. However, few studies have rigorously investigated the role of adult socioeconomic status (SES) as a mediator and an effect modifier of the association between ACEs and late-life depression. We used a four-way decomposition analysis to examine the relative contributions of mediation and interaction by low adult SES to the association between ACEs and late-life depression. METHODS: Data came from two waves (2013 and 2016) of the Japan Gerontological Evaluation Study, a nationwide cohort of older people (n = 7271). ACEs were determined as ≥ 2 experiences of the following: parental loss, parental divorce, parental mental illness, domestic violence, physical abuse, psychological neglect, psychological abuse, and economic disadvantage. Low adult SES was defined as earning < 2 million yen of income and < 10 years of schooling. Depressive symptoms were assessed using the Geriatric Depression Scale. RESULTS: Controlled direct effect (coefficient 0.28; 95% CI 0.08-0.46) accounted for 69.1% of the total effect, which was greater than the other three estimates for the decomposed effects (reference interaction 20.8%, mediated interaction 5.7%, and pure indirect effect 4.4%). Adult SES accounted for 10.1% (via mediation) and 26.5% (via exposure-mediator interaction) of the total association between ACEs and depressive symptoms, respectively. CONCLUSION: ACEs appeared to be a strong and independent determinant of depressive symptoms in later life. Nonetheless, the interaction between ACEs and adult SES indicates that achieving high adult SES could mitigate the adverse effect of ACEs on late-life depression.

Universal health coverage of five essential health services in mothers before and after the Haiti 2010 earthquake: a retrospective cohort study using difference-in-difference.

BACKGROUND: In January 2010, Haiti was hit by a 7.0-magnitude earthquake. The impact of the earthquake on Universal Health Coverage in mothers remains unclear. This study explores the association between the 2010 Haiti earthquake and access to the five quality essential health services among women who gave birth in the two years before and after the earthquake. METHODS: From the Sixth Demographic and Health Survey in Haiti, we extracted data for women aged 15-49 who had reported a live birth in the two years before and after the 2010 Haiti earthquake. We used difference-in-difference analyses for antenatal care, delivery care, and vaccination, and multivariate logistic regression analyses for family planning and malaria prevention, to assess the impact of the acute damage (household-level damage, such as housing damage and/or loss of a family member, or region-level damage, such as living in a region where 50% or more of the houses were damaged) of the earthquake on these mothers' access to quality essential health services. RESULTS: Mothers who had not suffered acute earthquake damage were more likely to live in rural areas and had less education and household wealth. The difference-in-difference and multivariate logistic regression analyses did not show strong evidence of any significant association between acute earthquake damage and access to quality health services. However, after the earthquake, access to quality health services deteriorated for both mothers with and without acute earthquake damage (-5.6% and -6.2% for antenatal care, -6.5% and 0% for delivery care, and -9.5% and -13.1% for vaccination, respectively). CONCLUSIONS: The earthquake adversely affected mothers' access to quality essential health services regardless of their exposure to acute earthquake damage. Mothers in rural areas who avoided such damage might also have experienced long-term negative effects from the earthquake, which was likely exacerbated by other structural factors such as lower education and economic status.

Uncovering heterogeneous associations of disaster-related traumatic experiences with subsequent mental health problems: A machine learning approach.

AIM: Understanding the differential mental health effects of traumatic experiences is important to identify particularly vulnerable subpopulations. We examined the heterogeneous associations between disaster-related traumatic experiences and postdisaster mental health, using a novel machine learning-based causal inference approach. METHODS: Data were from a prospective cohort study of Japanese older adults in an area severely affected by the 2011 Great East Japan Earthquake. The baseline survey was conducted 7 months before the disaster and the 2 follow-up surveys were conducted 2.5 and 5.5 years after (n = 1150 to n = 1644 depending on the exposure-outcome combinations). As disaster-related traumatic experiences, we assessed complete home loss and loss of loved ones. Using the generalized random forest algorithm, we estimated conditional average treatment effects (CATEs) of the disaster damages on postdisaster mental health outcomes to examine the heterogeneous associations by 51 predisaster characteristics of the individuals. RESULTS: We found that, even when there was no population average association between disaster-related trauma and subsequent mental health outcomes, some subgroups experienced severe impacts. We also identified and compared characteristics of the most and least vulnerable groups (ie, top versus bottom deciles of the estimated CATEs). While there were some unique patterns specific to each exposure-outcome combination, the most vulnerable group tended to be from lower socioeconomic backgrounds with preexisting depressive symptoms for many exposure-outcome combinations. CONCLUSIONS: We found considerable heterogeneity in the association between disaster-related traumatic experiences and subsequent mental health problems.

Optimism and Longevity Among Japanese Older Adults.

Background: Optimism has been linked to better physical health across various outcomes, including greater longevity. However, most evidence is from Western populations, leaving it unclear whether these relationships may generalize to other cultural backgrounds. Using secondary data analysis, we evaluated the associations of optimism among older Japanese adults. Methods: Data were from a nationwide cohort study of Japanese older adults aged ≥65 years (Japan Gerontological Evaluation Study; n = 10,472). In 2010, optimism and relevant covariates (i.e., sociodemographic factors, physical health conditions, depressive symptoms, and health behaviors) were self-reported. Optimism was measured using the Japanese version of the Life Orientation Test-Revised (LOT-R). Lifespan was determined using mortality information from the public long-term care insurance database through 2017 (7-year follow-up). Accelerated failure time models examined optimism (quintiles or standardized continuous scores) in relation to percent differences in lifespan. Potential effect modification by gender, income, and education was also investigated. Results: Overall, 733 individuals (7%) died during the follow-up period. Neither continuous nor categorical levels of optimism were associated with lifespan after progressive adjustment for covariates (e.g., in fully-adjusted models: percent differences in lifespan per 1-SD increase in continuous optimism scores= -1.2%, 95%CI: -3.4, 1.1 higher versus lower optimism quintiles= -4.1%, 95%CI: -11.2, 3.6). The association between optimism and lifespan was null across all sociodemographic strata as well. Conclusion: Contrary to the existing evidence from Western populations, optimism was unrelated to longevity among Japanese older adults. The association between optimism, as evaluated by the LOT-R, and longevity may differ across cultural contexts.

Associations of home confinement during COVID-19 lockdown with subsequent health and well-being among UK adults.

During the COVID-19 pandemic, the United Kingdom (UK) government introduced public health safety measures to mitigate the spikes in infection rates. This included stay-at-home orders that prevented people from leaving their homes for work or study, except for urgent medical care or buying essential items. This practice could have both short and long-term implications for health and wellbeing of people in the UK. Using longitudinal data of 10,630 UK adults, this study prospectively examined the association between home confinement status during the stringent lockdown in the UK (March 23-May 13, 2020) and 20 indicators of subjective well-being, social well-being, pro-social/altruistic behaviors, psychological distress, and health behaviors assessed approximately one month after the stringent lockdown ended. All analyses adjusted for socio-demographic characteristics and social isolation status in the beginning of the pandemic. Home confinement during the lockdown was associated with greater subsequent compliance with COVID-19 rules, more perceived major stressors, and a lower prevalence of physical activity. There was modest evidence of associations with lower life satisfaction, greater loneliness, greater depressive symptoms, greater anxiety symptoms, and more perceived minor stressors post-lockdown. However, there was little evidence that home confinement was associated with other indices of subsequent health and well-being. While our study shows that home confinement impacts some indices of subsequent health and wellbeing outcomes even after lockdown, the degree of the psychological adaptation to the difficult confinement behavior remains unclear and should be further studied. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-022-03001-5.

Causal Inference in Studying the Long-Term Health Effects of Disasters: Challenges and Potential Solutions.

Two frequently encountered but underrecognized challenges for causal inference in studying the long-term health effects of disasters among survivors include 1) time-varying effects of disasters on a time-to-event outcome and 2) selection bias due to selective attrition. In this paper, we review approaches for overcoming these challenges and demonstrate application of the approaches to a real-world longitudinal data set of older adults who were directly affected by the 2011 Great East Japan Earthquake and Tsunami (n = 4,857). To illustrate the problem of time-varying effects of disasters, we examined the association between degree of damage due to the tsunami and all-cause mortality. We compared results from Cox regression analysis assuming proportional hazards with those derived using adjusted parametric survival curves allowing for time-varying hazard ratios. To illustrate the problem of selection bias, we examined the association between proximity to the coast (a proxy for housing damage from the tsunami) and depressive symptoms. We corrected for selection bias due to attrition in the 2 postdisaster follow-up surveys (conducted in 2013 and 2016) using multivariable adjustment, inverse probability of censoring weighting, and survivor average causal effect estimation. Our results demonstrate that analytical approaches which ignore time-varying effects on mortality and selection bias due to selective attrition may underestimate the long-term health effects of disasters.

Estimating the Impact of Sustained Social Participation on Depressive Symptoms in Older Adults.

BACKGROUND: Social participation has been suggested as a means to prevent depressive symptoms. However, it remains unclear whether a one-time boost suffices or whether participation needs to be sustained over time for long-term prevention. We estimated the impacts of alternative hypothetical interventions in social participation on subsequent depressive symptoms among older adults. METHODS: Data were from a nationwide prospective cohort study of Japanese older adults ≥65 years of age (n = 32,748). We analyzed social participation (1) as a baseline exposure from 2010 (approximating a one-time boost intervention) and (2) as a time-varying exposure from 2010 and 2013 (approximating a sustained intervention). We defined binary depressive symptoms in 2016 using the Geriatric Depression Scale. We used the doubly robust targeted maximum likelihood estimation to address time-dependent confounding. RESULTS: The magnitude of the association between sustained participation and the lower prevalence of depressive symptoms was larger than the association observed for baseline participation only (e.g., prevalence ratio [PR] for participation in any activity = 0.83 [95% confidence interval = 0.79, 0.88] vs. 0.90 [0.87, 0.94]). For activities with a lower proportion of consistent participation over time (e.g., senior clubs), there was little evidence of an association between baseline participation and subsequent depressive symptoms, while an association for sustained participation was evident (e.g., PR for senior clubs = 0.96 [0.90, 1.02] vs. 0.88 [0.79, 0.97]). Participation at baseline but withholding participation in 2013 was not associated with subsequent depressive symptoms. CONCLUSIONS: Sustained social participation may be more strongly associated with fewer depressive symptoms among older adults.

General health checks and incident dementia: A six-year follow-up study of community-dwelling older adults in Japan.

General health checks to detect cardiovascular risk factors form part of routine health care in many countries. Cardiovascular disease and dementia share a number of risk factors; however it remains unclear whether general health checks can reduce the incidence of dementia. We used longitudinal data from the Japan Gerontological Evaluation Study with up to 6.4 years follow-up (from 2010 to 2016). A total of 31,012 disability-free adults aged 65-74 were included. The outcome variable was dementia onset certified under the national long-term care insurance system. The treatment variable was defined as having health checks within the past 12 months prior to the baseline survey in 2010. After multiple imputation, we performed propensity score matching (PSM) to exclude off-support individuals who were the least likely to have health checks. We also performed inverse probability treatment weighting (IPTW) to estimate the effect of the treatment if everyone within the population was compliant to health checks. The hazard ratios for dementia onset among those reporting health checks within the previous year was 0.89 (95% confidence interval (CI): 0.78, 1.02) in the PSM analysis and 0.84 (95% CI: 0.75, 0.95) in the IPTW analysis. We then estimated the effect of health checks on 5-year incident dementia. The 5-year cumulative incidence difference based on the PSM analysis was -0.0046 (95%CI: -0.0101, 0.0009), while that based on the IPTW analysis was -0.0046 (95%CI, -0.0090, -0.0002). The PSM and IPTW approaches yielded similar findings that the incidence of dementia was lower among people having health checks.

Using Propensity Scores for Causal Inference: Pitfalls and Tips.

Methods based on propensity score (PS) have become increasingly popular as a tool for causal inference. A better understanding of the relative advantages and disadvantages of the alternative analytic approaches can contribute to the optimal choice and use of a specific PS method over other methods. In this article, we provide an accessible overview of causal inference from observational data and two major PS-based methods (matching and inverse probability weighting), focusing on the underlying assumptions and decision-making processes. We then discuss common pitfalls and tips for applying the PS methods to empirical research and compare the conventional multivariable outcome regression and the two alternative PS-based methods (ie, matching and inverse probability weighting) and discuss their similarities and differences. Although we note subtle differences in causal identification assumptions, we highlight that the methods are distinct primarily in terms of the statistical modeling assumptions involved and the target population for which exposure effects are being estimated.

Can social capital moderate the impact of widowhood on depressive symptoms? A fixed-effects longitudinal analysis.

OBJECTIVES: Widowhood is associated with increased risks of depression in the surviving spouse. We examined whether an increase in individual-level social capital mitigates the adverse impact of widowhood on depressive symptoms. METHODS: We used data from the 2013/2016 waves of the Japan Gerontological Evaluation Study of functionally independent adults aged 65 years or older (men: n = 20,853; women: n =16,858). Fixed-effects regression was applied to examine the potential buffering effects of changes in social capital on changes in depressive symptoms following widowhood among married people living with their spouse and/or others at baseline. RESULTS: Widowhood had a deleterious impact on depressive symptoms particularly among men who ended up living alone following their spouse's death. Fixed-effects models revealed that an increase in informal socializing and social participation might buffer the effects of spousal bereavement on depressive symptoms among men who became widowed during the first two years of follow-up and ended up living alone. DISCUSSION: An increase in structural social capital may mitigate the impact of spousal bereavement on depressive symptoms. However, the associations vary by gender, living arrangement, and time since widowhood. Intensive efforts should be directed toward connecting the vulnerable group, widowed men living alone, to sources of social capital.

Cardiometabolic Profiles and Change in Neighborhood Food and Built Environment Among Older Adults: A Natural Experiment.

BACKGROUND: The association between neighborhood environment and health may be biased due to confounding by residential self-selection. The displacement of disaster victims can act as a natural experiment that exposes residents to neighborhood environments they did not select, allowing for the study of neighborhood effects on health. METHODS: We leveraged data from a cohort of older adults 65 years of age or older living in Iwanuma, Japan, located 80 km west of the 2011 Great East Japan Earthquake and Tsunami. Surveys were conducted 7 months before the disaster, as well as 2.5 and 5.5 years afterward, and linked with medical records. We classified each individual's type of exposure to neighborhood environment based on proximity to local food and recreation destinations and walkability. RESULTS: Fixed-effect models indicated that change in the exposure type from low to high urban density was associated with increased body mass index (0.46 kg/m; 95% confidence interval [CI] = 0.20, 0.73), waist circumference (1.8 cm; 95% CI = 0.56, 3.0), low-density lipoprotein cholesterol (11 mg/dl; 95% CI = 5.0, 17), and decreased high-density lipoprotein cholesterol (-3.1 mg/dl; 95% CI = -5.0, -1.3). We observed similar trends when we analyzed only the individuals who experienced postdisaster relocation to temporary homes. CONCLUSIONS: Increased proximity to food outlets was simultaneously correlated with greater walkability and accessibility to recreational destinations; however, any protective association of physical activity-promoting built environment appeared to be offset by proximity to unhealthy food outlets, especially fast-food restaurants and bars.