Volunteer group participation and subsequent health and well-being among older adults in Japan: An outcome-wide longitudinal approach.

BACKGROUND: Prior studies have underscored the importance of studying volunteering in the East Asian context. However, no study has conducted a holistic assessment of the relationship between volunteering and the multidimensional health and well-being outcomes of East Asian populations using a strong study design for causal inference. To address this gap, this study examined the associations between volunteer group participation and the subsequent health and well-being of Japanese older adults. METHODS: Three waves of data (2013, 2016, and 2019), obtained from the Japan Gerontological Evaluation Study-a nationwide cohort study of physically and cognitively independent older adults, aged ≥ 65 years, in Japan-were utilized. Exposure was evaluated as the frequency of volunteer group participation: ≥ 1/week, 1 - 3 times a month, a few times a year, and none (2016). As outcomes, 40 indicators of health and well-being were assessed across seven domains (2019): physical/cognitive health, health behaviors, mental health, subjective well-being, social well-being, pro-social/altruistic behaviors, and cognitive social capital. We included 47,318 respondents for four outcomes (death, dementia, and functional disability [any level and level 2 or greater]) and 34,187 respondents for the 36 other outcomes. RESULTS: More frequent volunteering (≥ 1/week) was associated with higher social well-being outcomes, more frequent pro-social/altruistic behaviors and outings, and fewer depressive symptoms, even after considering multiple testing. CONCLUSION: Throughout the three-year follow-ups, volunteer group participation was beneficial for depressive symptoms, social well-being, and other proximal outcomes.

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.

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.

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.

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.

Sense of Coherence and Incident Dementia in Older Japanese Adults: The Japan Gerontological Evaluation Study.

OBJECTIVES: The sense of coherence refers to effectively using available resources to manage stress and promote overall health. Previous studies have linked it to various health outcomes; however, evidence regarding its association with the risk of incident dementia is limited. Hence, this study aimed to fill this research gap using data from a large-scale population survey. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: This study included 31,556 participants aged 65 years and older who were free from dementia and disabilities. The participants were enrolled in the 2010 baseline survey of the Japan Gerontological Evaluation Study, and were followed up until the end of 2019. METHODS: The sense of coherence was assessed using a 6-item short-version questionnaire. Incident dementia cases were ascertained through the public long-term care insurance database in Japan. RESULTS: During a median follow-up of 8.3 years, 4326 incident dementia cases were identified. After adjusting for conventional risk factors, the hazard ratios (95% CIs) for each quintile compared to the lowest quintile of the sense of coherence were 0.82 (0.75-0.90), 0.75 (0.68-0.83), 0.76 (0.68-0.84), and 0.78 (0.70-0.87), respectively. The multivariable hazard ratio (95% CI) per 1-SD increment was 0.91 (0.88-0.95). These inverse associations did not exhibit any gender differences (P for gender interaction = .11) and were further confirmed after excluding early incident cases. Similar associations were found for its components; the corresponding multivariable hazard ratios (95% CIs) per 1-SD increment were 0.94 (0.91-0.97) for comprehensibility, 0.92 (0.89-0.95) for manageability, and 0.93 (0.90-0.97) for meaningfulness. CONCLUSIONS AND IMPLICATIONS: Moderate and above sense of coherence was associated with the lower risk of dementia among the older population, suggesting a beneficial role of stress management in maintaining the cognitive health of older adults.

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.

Participation in Community Gathering Places and Subsequent Health and Well-Being: An Outcome-Wide Analysis.

Background and Objectives: Evidence remains inadequate regarding the benefits of participation in community gathering places, which is Japan's primary strategy for preventing functional disability in older adults, in other domains of health and well-being. This longitudinal study examined the associations of participation in community gathering places with an array of subsequent health and well-being outcomes among older adults. Research Design and Methods: We used 3-wave data (2013, 2016, and 2019) from Japan Gerontological Evaluation Study (n = 5 879 or 4 232 depending on the outcome). Our exposure was participation in community gathering places in 2016. We assessed 34 health/well-being outcomes in 2019 across 6 domains. We adjusted for pre-baseline covariates including prior outcome values in 2013. Results: Compared with nonparticipation, participation in community gathering places was associated with some outcomes in the following 3 domains: physical/cognitive health (better higher-level functional capacity), social well-being (more frequent participation in hobby groups, senior citizens clubs, learning or cultural groups, and seeing more friends within a month), and prosocial/altruistic behaviors (more frequent participation in volunteering; after Bonferroni correction as p < .0015, .05/34). Discussion and Implications: Evidence was mixed and more modest for the outcomes in three other domains, mental health, psychological well-being, and health behaviors. Promoting participation in community gathering places may not only fulfill its original goal (ie, preventing functional disability) but also enhance other domains of human well-being, potentially by increasing social interactions.

Association between sense of coherence and health and well-being among older survivors of a natural disaster: a prospective outcome-wide study.

We examined whether pre-disaster Sense of Coherence (SOC) mitigated the impact of housing damage on health and well-being of older survivors after the 2011 Japan Earthquake and Tsunami. A panel survey was conducted in a city located 80 km west of the epicenter seven months before and three years after the disaster (3594 respondents). Among respondents with lighter property damage, higher SOC was inversely associated with mental distress (coefficient - 0.29, 95% CI (confidence interval) - 0.39, - 0.19, p < .01), unhappiness (coefficient - 0.33, 95% CI - 0.43, - 0.23, p < .01), low expectation of mutual help (coefficient - 0.17, 95% CI - 0.27, - 0.07, p < .01), and weak community attachment (coefficient - 0.20, 95% CI - 0.30, - 0.11, p < .01). Conversely, among those who experienced housing loss, higher SOC was no longer protectively associated with health and well-being. Loss of generalized resistance resources due to serious damage led to difficulties in stress coping.

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.

Exploring the relationship between oral health and multiple health conditions: An outcome-wide approach.

PURPOSE: A growing body of evidence suggests that oral health is associated with a wide range of health outcomes; however, opinions tend to vary because of inconsistent findings. This study aimed to simultaneously examine the association between oral health status and multiple health and well-being indicators using outcome-wide epidemiology. METHODS: Data were obtained from the Japan Gerontological Evaluation Study. Oral health status was categorized as: ≥20 teeth, 10-19 teeth with dental prosthesis, 0-9 teeth with prosthesis, 10-19 teeth without prosthesis, and 0-9 teeth without prosthesis. We examined the associations between oral health status in 2013 and 35 health and well-being outcomes in 2019, including physical/cognitive health, psychological distress, subjective health, social well-being, prosocial/altruistic behaviors, and health behaviors, using two databases (n=32,827 and 15,905). RESULTS: Compared to individuals with ≥20 teeth, those with <20 teeth had a 10-33% higher risk of mortality and a 7-10% higher risk of functional disability six years later. Additionally, individuals with fewer than 20 teeth tended to go out less frequently and eat fewer vegetables and fruits. Furthermore, individuals with 0-9 teeth without a prosthesis were more likely to have severe functional disability (risk ratio (RR):1.17, 95% confidence interval (CI):1.05-1.31), engage in fewer intellectual activities (standardized difference: 0.17, 95% CI: 0.10-0.24), and feel more hopeless (RR: 1.21, 95% CI: 1.04-1.41). CONCLUSIONS: The prevention of tooth loss and prosthodontic treatment may be associated with reduced mortality and functional disability, as well as maintenance of intellectual ability, frequency of going out, and improvements in dietary lifestyle.

Are loneliness and social isolation equal threats to health and well-being? An outcome-wide longitudinal approach.

The detrimental effects of loneliness and social isolation on health and well-being outcomes are well documented. In response, governments, corporations, and community-based organizations have begun leveraging tools to create interventions and policies aimed at reducing loneliness and social isolation at scale. However, these efforts are frequently hampered by a key knowledge gap: when attempting to improve specific health and well-being outcomes, decision-makers are often unsure whether to target loneliness, social isolation, or both. Filling this knowledge gap will inform the development and refinement of effective interventions. Using data from the Health and Retirement Study (13,752 participants (59% women and 41% men, mean [SD] age = 67 [10] years)), we examined how changes in loneliness and social isolation over a 4-year follow-up period (from t0:2008/2010 to t1:2012/2014) were associated with 32 indicators of physical-, behavioral-, and psychosocial-health outcomes 4-years later (t2:2016/2018). We used multiple logistic-, linear-, and generalized-linear regression models, and adjusted for sociodemographic, personality traits, pre-baseline levels of both exposures (loneliness and social isolation), and all outcomes (t0:2008/2010). We incorporated data from all participants into the overall estimate, regardless of whether their levels of loneliness and social isolation changed from the pre-baseline to baseline waves. After adjusting for a wide range of covariates, we observed that both loneliness and social isolation were associated with several physical health outcomes and health behaviors. However, social isolation was more predictive of mortality risk and loneliness was a stronger predictor of psychological outcomes. Loneliness and social isolation have independent effects on various health and well-being outcomes and thus constitute distinct targets for interventions aimed at improving population health and well-being.

Social isolation and subsequent health and well-being in older adults: A longitudinal outcome-wide analysis.

BACKGROUND: Social isolation has become a serious public health issue. However, most previous studies examine the relationship between social isolation and a single outcome. We aimed to conduct holistic assessments to understand the multidimensional impacts of social isolation on health and well-being. METHODS: We used the three-wave data (2013, 2016, and 2019) obtained from the Japan Gerontological Evaluation Study. Our exposure, obtained from the 2016 survey, was the Social Isolation Index (SII) comprising five components: no partner, poor interaction with children, poor interaction with relatives, poor interaction with friends, and no social participation). We assessed 36 health and well-being outcomes across six dimensions obtained from the 2019 survey: physical/cognitive health, health behaviours, mental health, subjective well-being, social isolation, and cognitive social capital. Pre-exposure characteristics and prior outcome levels in 2013 were adjusted. We included 47,318 respondents for 4 outcomes (death, dementia, and functional disability) and 34,187 respondents for 32 other outcomes. The Bonferroni correction was used to correct for multiple tests. RESULTS: The total SII scores were associated with a wide range of health and well-being outcomes across the six dimensions. Specifically, we found a robust association between an SII score of four or greater with mortality (Odds ratio: 1.89; 95% CI: 1.46-2.43). Among the five components of the SII, poor interaction with friends and no social participation showed robust associations with a wide range of health and well-being. We also found some robust evidence regarding effect modification by gender and age in the associations between the components of the SII and health and well-being. CONCLUSIONS: Social isolation, specifically social interaction with friends and social participation, may affect a wide range of health and well-being among older adults.

Bidirectional associations between post-traumatic stress symptoms and sleep quality among older survivors of the 2011 Great East Japan Earthquake and Tsunami.

STUDY OBJECTIVES: We sought to examine the bidirectional associations between post-traumatic stress symptoms (PTSS) and sleep quality in a sample of older disaster survivors. METHODS: We used 4 waves (2010, 2013, 2016, and 2020) of the Iwanuma Study, which included pre-disaster information and 9 years of follow-up data among older survivors of the 2011 Great East Japan Earthquake and Tsunami. Poisson regression analysis was used to examine the bidirectional associations between sleep problems and PTSS. RESULTS: Individuals reporting sleep problems before the disaster were more likely to develop PTSS after exposure to disaster trauma, while there was no effect modification, i.e. prevalence ratio for sleep problems did not differ by the magnitude of disaster damages. Individuals reporting sleep problems after the disaster were less likely to recover from PTSS, and more likely to develop the delayed onset of PTSS 5 years after the disaster. While individuals who recovered from PTSS 9 years after the disaster were still at slightly higher risk of having sleep problems compared to those who never had PTSS, none of the sleeping problems were found to be significantly prevalent after the Bonferroni correction. CONCLUSIONS: Pre-disaster sleep problems predicted PTSS onset independently of experiences of disaster trauma. The association between PTSS and sleep problems was bidirectional. Intervening to mitigate lingering sleep problems may benefit the recovery of disaster survivors from post-traumatic symptoms.

Residential instability during adolescence and health and wellbeing in adulthood: A longitudinal outcome-wide study.

Although prior research suggests that residential instability during adolescence can have long-term impacts on health and wellbeing, few studies have identified a robust comparison group and considered a broad set of outcomes. To address these knowledge gaps, we examined the associations between residential instability during adolescence and a wide range of adult health and wellbeing outcomes using an outcome-wide design in the National Longitudinal Study of Adolescent to Adult Health. We defined residential instability as two or more moves between Waves I and II (ages 13-18 years). We assessed outcomes at ages 33-43 years (Wave V) in nine domains: biomarkers, physical health, health behaviors, psychological distress, psychological wellbeing, social behaviors, social wellbeing, trauma/victimization, and socioeconomic attainment. Results of doubly-robust targeted maximum likelihood estimation, adjusting for pre-exposure values of the outcome variables and cofounders (Wave I), showed little evidence of an association for certain outcomes, all of which disappeared after accounting for multiple comparisons. Our results suggest that residential instability in adolescence does not lead to worse health and wellbeing in adulthood, but rather, outcome differences between groups are due to pre-existing differences prior to residential instability in adolescence.

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.

Social Isolation and Depressive Symptoms Among Older Adults: A Multiple Bias Analysis Using a Longitudinal Study in Japan.

PURPOSE: Despite the potential burden of social isolation on mental health, it is unclear which component of social isolation (living alone, lack of social support, and lack of social participation) is mostly associated with depression among older adults and whether it varies by gender. Moreover, previous observational studies have suffered from several systematic biases such as confounding, misclassification, and selection bias. We thus aimed to investigate the risk of social isolation on subsequent depressive symptoms among older men and women, fully taking account of such systematic biases simultaneously. METHODS: This study included 15,311 adults from a nationwide longitudinal cohort study of older adults aged ≥65 years in Japan. We employed modified Poisson regression models to estimate the adjusted risk ratio (aRR) of elevated depressive symptoms (the Geriatric Depression Scale: ≥5 vs. <5) in 2016 according to the social isolation index (SII) score (0-5 points) in 2013. Non-probabilistic multiple bias analyses with weighting approach and bounding factor were conducted to adjust for possible confounding, exposure misclassification, and selection biases. RESULTS: The mean age (SD) of participants was 72.1 (4.9) years. Adults with the SII score ≥2 showed an increased risk of elevated depressive symptoms than those with the SII score <2 (aRR [95% CI] = 1.57 [1.41-1.76]). All components of SII were associated with elevated depressive symptoms except living alone for women. Our multiple bias analysis showed that an unmeasured confounder needed to have at least moderate relationship (RR=2.0-3.0) with both exposure and outcome to explain away the observed association particularly when social isolation status was independently and non-differentially misclassified. CONCLUSION: Among older adults in Japan, social isolation was associated with an increased risk of elevated depressive symptoms, even after taking account of systematic biases simultaneously. Increasing social connection may mitigate the risk of depression, which should be the subject of future research.

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.

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.

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.