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.

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 (β = 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 (β = 0·20, 95% CI = 0·12, 0·28, p < 0.001)), 4 (of 7) social outcomes (e.g., lower loneliness (β = -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.

Heterogeneous Association of Tooth Loss with Functional Limitations

Tooth loss is prevalent in older adults and associated with functional capacity decline. Studies on the susceptibility of some individuals to the effects of tooth loss are lacking. This study aimed to investigate the heterogeneity of the association between tooth loss and higher-level functional capacity in older Japanese individuals employing a machine learning approach. This is a prospective cohort study using the data of adults aged ≥65 y in Japan (N = 16,553). Higher-level functional capacity, comprising instrumental independence, intellectual activity, and social role, was evaluated using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC). The scale ranged from 0 (lowest function) to 13 (highest function). Doubly robust targeted maximum likelihood estimation was used to estimate the population-average association between tooth loss (having <20 natural teeth) and TMIG-IC total score after 6 y. The heterogeneity of the association was evaluated by estimating conditional average treatment effects (CATEs) using the causal forest algorithm. The result showed that tooth loss was statistically significantly associated with lower TMIG-IC total scores (population-average effect: -0.14; 95% confidence interval, -0.18 to -0.09). The causal forest analysis revealed the heterogeneous associations between tooth loss and lower TMIG-IC total score after 6 y (median of estimated CATEs = -0.13; interquartile range = 0.12). The high-impact subgroup (i.e., individuals with estimated CATEs of the bottom 10%) were significantly more likely to be older and male, had a lower socioeconomic status, did not have a partner, and had poor health conditions compared with the low-impact subgroup (i.e., individuals with estimated CATEs of the top 10%). This study found that heterogeneity exists in the association between tooth loss and lower scores on functional capacity. Implementing tooth loss prevention policy and clinical measures, especially among vulnerable subpopulations significantly affected by tooth loss, may reduce its burden more effectively.

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 Consideration

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. Jawadekar et al. (Am J Epidemiol. 2023) introduce this innovative approach and offer 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 the following 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 epidemiological research.

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.

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.

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.

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.

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.

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.

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 β = 0.25; 0.11-0.39) and happiness (standardized β = 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.

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.

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.

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.

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.

Post-Disaster Mental Health and Dietary Patterns among Older Survivors of an Earthquake and Tsunami

OBJECTIVES

Research suggests that cardiometabolic disease risks are elevated among survivors of natural disasters, possibly mediated by changes in diet. Using the Brief Dietary History Questionnaire, we examined (1) dietary patterns among older survivors of the 2011 Great East Japan Earthquake and Tsunami, and (2) the contribution of posttraumatic stress symptoms (PTSS)/depressive symptoms, as well as relocation to temporary housing on dietary patterns and (3) gender differences in the associations.

DESIGN, SETTING AND PARTICIPANTS

Data came from a prospective cohort study of 1,375 survivors aged 65-89 years (44.6% male).

MEASUREMENTS

PTSS/depression onset was evaluated in 2013, 2.5 years after the disaster. Dietary data was collected with a self-administered brief-type diet history questionnaire in 2020. A principal component analysis identified three posterior dietary patterns.

RESULTS

Diet 1 consisted of high intake of vegetables, soy products, and fruits; Diet 2 consisted of carbohydrate-rich foods and snacks/sweets; Diet 3 consisted of high intake of alcoholic beverages, meat, and seafood. Least-squares linear regression revealed that individuals with PTSS/depression were less likely to exhibit Diet 1, while individuals with PTSS were more likely to exhibit Diet 2 and 3. Especially, males who had depression showed an unhealthy dietary pattern. Those who have lived in a trailer-style temporary housing reported less consumption of Diet 3.

CONCLUSION

Survivors of disaster with symptoms of mental illness tended to exhibit less healthy dietary patterns after 9 years. Diet varied by type of post-disaster mental illness, gender, and current social circumstances. We lacked pre-disaster BDHQ data, which is a limitation.

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.

Complexifying Individualism Versus Collectivism and West Versus East: Exploring Global Diversity in Perspectives on Self and Other in the Gallup World Poll

A wealth of research has suggested the West tends toward individualism and the East toward collectivism. We explored this topic on an unprecedented scale through two new items in the 2020 Gallup World Poll, involving 121,207 participants in 116 countries. The first tapped into orientations toward self-care versus other-care (“Do you think people should focus more on taking care of themselves or on taking care of others?”). The second enquired into self-orientation versus other-orientation (“Which of the following is closest to your main purpose in life? Being good at what you do in your daily life, Caring for family and close friends, or Helping other people who need help?”). We anticipated that self-care and self-orientation would index individualism (hence be higher in the West), while other-care and other-orientation would index collectivism (hence be higher in the East). However, contrary to expectation, there was greater self-care in the East (45.82%) than in the West (41.58%). As predicted though, there was greater self-orientation in the West (30.20%) than in the East (23.08.%). Greater self-care in the East invites one of two interpretations. Either these items: (a) index individualism and collectivism as anticipated, so in some ways the East is more individualistic and the West less individualistic than assumed; or (b) do not index individualism and collectivism as anticipated, so the concepts are more complex than often realized (e.g., collectivism may involve prioritizing self-care over other-care). Either way, the findings help complexify these concepts, challenging common cross-cultural generalizations in this area.

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.

Long-Term Trend in the Association Between Disaster Damage and Happiness Before and After the Great East Japan Earthquake

Objectives: Disasters change survivors’ living circumstances, which can affect their happiness. We examined the trends in the association between disaster damage and happiness before and after a disaster.

Methods: We analyzed 4,044 participants aged ≥65 years who had experienced the Great East Japan Earthquake in 2011. The baseline survey was conducted 7 months before the disaster. Follow-up surveys have been conducted every 3 years. Using a mixed model for repeated measures, we compared the prevalence ratios (PRs) for unhappiness according to the survivors’ level of housing damage, which is a proxy for disaster damage.

Results: The unhappiness in participants who suffered severe damage appeared to be higher than in those with no damage in 2010 (multivariate-adjusted PR: 1.18, 95% confidence interval: 0.93–1.48). A higher PR was observed after the earthquake in 2013 (1.34, 0.79–2.28), while there was no difference in 2016 (1.02, 0.53–1.97) and 2019 (1.03, 0.50–2.12).

Conclusion: The prevalence of unhappiness in survivors with severe housing damage was higher before the disaster. However, the unhappiness gap between people with and without housing damage converged during the follow-up.

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.

Sense of purpose in life and inflammation in healthy older adults: A longitudinal study

BACKGROUND

A higher sense of purpose in life has been linked with reduced risk of age-related chronic health conditions that share elevated inflammation as a key risk factor (e.g., neurodegenerative diseases, heart disease, and diabetes). While prior research has documented cross-sectional associations between higher sense of purpose and lower inflammation, few studies have examined the association between purpose and changes in inflammation over time.

OBJECTIVE

We tested if a higher sense of purpose was prospectively associated with lower likelihood of developing unhealthy C-reactive protein levels in older adults who initially had healthy CRP levels (i.e., <3 ug/mL).

METHODS

Participants were 6925 adults aged > 50 in the Health and Retirement Study who were followed for 8 years. Participants completed the purpose in life subscale of the Ryff Psychological Well-being Scales at study baseline in 2006/2008. CRP was obtained from blood spots collected at baseline and after 4 and 8 years of follow-up. Pooled logistic regression estimated discrete-time hazard ratios (HR) and 95% confidence intervals (CI) for the association between baseline purpose and onset of unhealthy CRP levels (>3 ug/mL).

RESULTS

There was no strong evidence of an association between baseline continuous purpose scores and onset of unhealthy CRP levels over time in the overall analytic sample. In sex-stratified models, higher purpose was associated with lower hazards of developing unhealthy CRP levels among men, while associations were null in women (e.g., in sociodemographics-adjusted model, men: HR=0.89, 95% CI: 0.79-0.99; women: HR=0.96, 95% CI: 0.85-1.08; interaction between continuous purpose scores and sex p = 0.15).

CONCLUSIONS

Findings suggest that a higher versus lower sense of purpose is associated with lower inflammation levels in older men. In specific populations, purpose may serve as a novel target for future interventions aimed at reducing inflammation.

Long-Term Associations between Disaster-Related Home Loss and Health and Well-Being of Older Survivors: Nine Years after the 2011 Great East Japan Earthquake and Tsunami

BACKGROUND

Little research has examined associations between disaster-related home loss and multiple domains of health and well-being, with extended long-term follow-up and comprehensive adjustment for pre-disaster characteristics of survivors.

OBJECTIVES

We examined the longitudinal associations between disaster-induced home loss and 34 indicators of health and well-being, assessed ∼9y post-disaster.

METHODS

We used data from a preexisting cohort study of Japanese older adults in an area directly impacted by the 2011 Japan Earthquake (n=3,350 and n=2,028, depending on the outcomes). The study was initiated in 2010, and disaster-related home loss status was measured in 2013 retrospectively. The 34 outcomes were assessed in 2020 and covered dimensions of physical health, mental health, health behaviors/sleep, social well-being, cognitive social capital, subjective well-being, and prosocial/altruistic behaviors. We estimated the associations between disaster-related home loss and the outcomes, using targeted maximum likelihood estimation and SuperLearner. We adjusted for pre-disaster characteristics from the wave conducted 7 months before the disaster (i.e., 2010), including prior outcome values that were available.

RESULTS

After Bonferroni correction for multiple testing, we found that home loss (vs. no home loss) was associated with increased posttraumatic stress symptoms (standardized difference=0.50; 95% CI: 0.35, 0.65), increased daily sleepiness (0.38; 95% CI: 0.21, 0.54), lower trust in the community (-0.36; 95% CI: -0.53, -0.18), lower community attachment (-0.60; 95% CI: -0.75, -0.45), and lower prosociality (-0.39; 95% CI: -0.55, -0.24). We found modest evidence for the associations with increased depressive symptoms, increased hopelessness, more chronic conditions, higher body mass index, lower perceived mutual help in the community, and decreased happiness. There was little evidence for associations with the remaining 23 outcomes.

DISCUSSION

Home loss due to a disaster may have long-lasting adverse impacts on the cognitive social capital, mental health, and prosociality of older adult survivors. https://doi.org/10.1289/EHP10903.

Application of Causal Inference Methods in the Analysis of Observational Neurosurgical Data: G-Formula and Marginal Structural Model

OBJECTIVE

When using observational data to estimate the causal effects of a treatment on clinical outcomes, we need to adjust for confounding. In the presence of time-dependent confounders that are affected by previous treatment, adjustments cannot be made via the conventional regression approach or propensity score-based methods, but requires sophisticated methods called g-methods. We aimed to introduce g-methods to estimate the causal effects of treatment strategies defined by treatment at multiple time points, such as treat 2 days versus treat only day 1 versus never-treat.

METHODS

Two g-methods were introduced: the g-formula and inverse probability-weighted marginal structural models. Under exchangeability, consistency, and positivity assumptions, they provide a consistent estimate of the causal effects of the treatment strategy.

RESULTS

Using a numeric example that mimics the observational study data, we presented how the g-formula and inverse probability-weighted marginal structural models can estimate the effect of the treatment strategy.

CONCLUSIONS

Both g-formula and inverse probability-weighted marginal structural models can correctly estimate the effect of the treatment strategy under 3 identifiability assumptions, which conventional regression analysis cannot. G-methods may assist in estimating the effect of treatment strategy defined by treatment at multiple time points.

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.

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.

Global Trends of Mean and Inequality in Multidimensional Wellbeing: Analysis of 1.2 Million Individuals From 162 Countries, 2009–2019

Introduction

Human flourishing is a multidimensional concept characterized by a state of complete wellbeing. However, much of the prior research on wellbeing has principally focused on population averages assessed using a single item of wellbeing. This study examined trends in population averages and inequalities for a multidimensional index of wellbeing and compared emergent patterns with those found for Cantril's ladder, a measure of life satisfaction commonly used as a unidimensional index of wellbeing.

Methods

Data were from the Gallup World Poll from the years 2009 to 2019, a repeated cross-sectional survey of nationally representative samples comprising ~1.2 million individuals from 162 countries. We assessed five domains of flourishing: (1) happiness, (2) health, (3) purpose, (4) character, and (5) social relationships. We used the Gini Index to estimate inequalities in wellbeing within populations. We examined and compared country ranking, global and region-specific trajectories of mean and inequality, and relationships with age for flourishing and Cantril's ladder.

Results

Although all trends were highly correlated across the two metrics of wellbeing, we identified distinct patterns in flourishing concerning geography, time, and age relationships that were not observed for Cantril's ladder. Temporal trends and age relationships were different across domains of flourishing. Evidence of changing inequalities in wellbeing was also found, even when population averages were high or stable over time.

Conclusion

Comprehensive measures of wellbeing are needed to capture the complex and changing patterns of wellbeing both within and across populations.

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.

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.

Heterogeneity in cognitive disability after a major disaster: A natural experiment study

Cognitive disability following traumatic experiences of disaster has been documented; however, little is known about heterogeneity in the association across individuals. In this natural experiment study of approximately 3000 Japanese older adults in an area directly affected by the 2011 Great East Japan Earthquake, the baseline survey was established 7 months before the 2011 earthquake. To inductively identify heterogeneity in postdisaster cognitive disability by predisaster characteristics, we applied a machine learning–based causal inference approach—generalized random forest. We identified strong evidence for heterogeneity in the association between home loss and cognitive disability objectively assessed 2.5 and 5.5 years after the 2011 earthquake. The subgroups with the strongest disaster-dementia associations tended to be from low socioeconomic backgrounds and have predisaster health problems. The study demonstrated that some subpopulations are particularly prone to experience cognitive disability after disasters, which could be overlooked in studies assessing population average associations only.

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.

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.

Associations Between Purpose in Life and Mortality by SES

INTRODUCTION

Having a higher purpose in life has been linked to favorable health outcomes. However, little research has examined whether the purpose-health association persists across different levels of SES. This study assesses whether the association between higher purpose in life and lower mortality is similar across the levels of SES.

METHODS

A national sample of 13,159 U.S. adults aged >50 years from the Health and Retirement Study was analyzed. The baseline year was 2006‒2008. Purpose in life was assessed at baseline using Purpose in Life Subscale of the Ryff Psychological Well-being Scales. The risk of death during an 8-year follow-up was assessed. SES was measured using education, income, and wealth. Using multivariable Poisson regression, effect modification by SES was tested on both the additive and multiplicative scales. Analyses were done in 2020.

RESULTS

In analyses stratified by SES, people with the highest level of purpose consistently tended to have lower mortality risk across the levels of SES than those with the lowest level of purpose. However, people with middle-range purpose levels had lower mortality risk only if they also had mid-to-high education, income, and wealth. When formally testing the effect modification by SES, there was modest evidence that the associations between higher purpose and lower mortality were stronger among individuals with high education, income, and wealth.

CONCLUSIONS

The highest level of purpose appeared protective against all-cause mortality regardless of the levels of SES. By contrast, when levels of purpose were more modest, people with lower SES may benefit less health-wise from having a purpose.

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.

A scoping review on the use of machine learning in research on social determinants of health: Trends and research prospects

Background

Machine learning (ML) has spread rapidly from computer science to several disciplines. Given the predictive capacity of ML, it offers new opportunities for health, behavioral, and social scientists. However, it remains unclear how and to what extent ML is being used in studies of social determinants of health (SDH).

Methods

Using four search engines, we conducted a scoping review of studies that used ML to study SDH (published before May 1, 2020). Two independent reviewers analyzed the relevant studies. For each study, we identified the research questions, Results, data, and algorithms. We synthesized our findings in a narrative report.

Results

Of the initial 8097 hits, we identified 82 relevant studies. The number of publications has risen during the past decade. More than half of the studies (n = 46) used US data. About 80% (n = 66) utilized surveys, and 70% (n = 57) employed ML for common prediction tasks. Although the number of studies in ML and SDH is growing rapidly, only a few studies used ML to improve causal inference, curate data, or identify social bias in predictions (i.e., algorithmic fairness).

Conclusions

While ML equips researchers with new ways to measure health outcomes and their determinants from non-conventional sources such as text, audio, and image data, most studies still rely on traditional surveys. Although there are no guarantees that ML will lead to better social epidemiological research, the potential for innovation in SDH research is evident as a result of harnessing the predictive power of ML for causality, data curation, or algorithmic fairness.

Can Online Communication Prevent Depression Among Older People? A Longitudinal Analysis

Evidence on the association between internet usage and incidence of depression remains mixed. We examined the associations between different categories of internet usage and developing clinical depression. We used data from the 2013 and 2016 waves of the Japan Gerontological Evaluation Study (JAGES) comprising 12,333 physically and cognitively independent adults aged ≥65 years. Participants were engaged in seven categories of internet usage: communication with friends/family, social media, information collection about health/medicine, searching for medical facilities, purchase of drugs and vitamins, shopping, and banking. We found that internet use for communication had a protective influence on the probability of developing clinical depression defined as the Geriatric Depression Scale scores ≥5 or self-reported diagnosed depression. Our findings support the role of online communication with friends/family in preventing clinical depression among older people. Online communication could be particularly useful in the COVID-19 crisis because many families are geographically dispersed and/or socially distanced.

Depressive symptoms in the aftermath of major disaster: Empirical test of the social support deterioration model using natural experiment

INTRODUCTION

We examined the extent to which the post-disaster deterioration of social support and social capital mediates the associations between disaster-related experiences and depressive symptoms among survivors to test the social support deterioration model.

METHODS

We used unique natural experiment data (n = 3567) stemming from the 2011 Great East Japan Earthquake. The follow-up survey was conducted 2.5 years after the disaster. We examined associations between changes in depressive symptoms, disaster-related experiences (loss of loved ones, changes in household income, loss of job, drop in subjective economic status, and home loss), and post-disaster deterioration of four different types of social support (i.e., kin emotional, kin instrumental, non-kin emotional, and non-kin instrumental support), as well as two dimensions of individual-level social capital (i.e., informal socializing and social cohesion). We then performed causal mediation analysis.

RESULTS

We found that there was deterioration of social support and social capital among individuals with disaster-related experiences. We also found associations between deterioration of social support/capital and worsening of depressive symptoms for specific categories of disaster experiences (i.e., drop in subjective economic status, loss of job, and home loss). However, causal mediation analysis showed little evidence of mediation by post-disaster deterioration of social support/capital. There was some evidence to suggest exposure-mediator interaction such that the association between social support/capital deterioration and depressive symptoms was weaker among those with disaster experiences.

DISCUSSION

The social support deterioration model was not empirically supported among older-adult disaster survivors of the 2011 Great East Japan Earthquake, after accounting for exposure-mediator interactions.

Sense of purpose in life and five health behaviors in older adults

Accumulating evidence shows that a higher sense of purpose in life is associated with lower risk of chronic conditions and premature mortality. Health behaviors might partially explain these findings, however, the prospective association between sense of purpose and health behaviors is understudied. We tested whether a higher sense of purpose at baseline was associated with lower likelihood of developing unhealthy behaviors over time. Prospective data were from the Health and Retirement Study, a national sample of U.S. older adults. Our sample included 13,770 adults assessed up to five times across eight years. Among people who met recommended guidelines for a given health behavior outcome at baseline, those in the top versus lowest quartile of purpose in life had 24% lower likelihood of becoming physically inactive (95% CI: 0.68-0.85), 33% lower likelihood of developing sleep problems (95% CI: 0.58-0.79), and 22% lower likelihood of developing unhealthy body mass index (BMI) (95% CI: 0.69-0.87) in sociodemographic-adjusted models. Further there was a marginal reduction in smoking relapse (HR = 0.65, 95% CI: 0.41-1.03) and no association with heavy alcohol use (HR = 1.02, 95% CI: 0.81-1.29). Findings for physical inactivity, sleep problems, and unhealthy BMI remained evident after further adjusting for baseline health status and depression. Our results, suggest that a sense of purpose in life might emerge (with further research) as a valuable target to consider for interventions aimed at helping older adults maintain some health behaviors.

Does community-level social capital mitigate the impact of widowhood & living alone on depressive symptoms?: A prospective, multi-level study

Widowhood and living alone are linked to increased risk of depression. We examined prospectively whether community-level social capital can mitigate the adverse impact of widowhood and living alone on depressive symptoms. We used data of the Japan Gerontological Evaluation Study of functionally independent adults aged 65 years or older. Three waves of surveys were collected in 2010, 2013 and 2016. We conducted gender-stratified multilevel linear regression to examine the moderating effects of community-level social capital on depressive symptoms (as assessed by the 15-point Geriatric Depression Scale) associated with widowhood and living alone. Widowhood in the past 12 months in combination with living alone was associated with a marked worsening in depressive symptoms among men (beta coefficient = 1.67; 95% confidence interval: 1.38, 1.95). Community-level civic participation, but not social cohesion or reciprocity, was associated with lower depressive symptoms in men and women. In addition, community-level civic participation moderated the association between depressive symptoms and recent widowhood/living alone among men (coefficient per 1 standard deviation = -0.30; 95% confidence interval: -0.59, -0.02). We found no significant effect modification of community-level social capital on depressive symptoms associated with widowhood and living alone among women. Communities with greater civic participation appear to mitigate the onset of depressive symptoms among recently widowed men living alone. Promotion of community activities might be an effective community-level intervention to promote mental health in this vulnerable group.

Sarcopenic obesity is associated with a faster decline in renal function in people with type 2 diabetes

AIM

To evaluate the association between sarcopenic obesity and the decline in estimated GFR in people with type 2 diabetes.

METHODS

We enrolled 745 people with type 2 diabetes (mean age 64.6 years, 53.6% men). Body composition was evaluated using dual-energy X-ray absorptiometry. Skeletal muscle index, calculated as appendicular non-fat mass (kg) divided by height squared (m² ), was used to determine sarcopenia. Sarcopenic obesity was defined as the coexistence of sarcopenia and a ratio of android to gynoid fat mass greater than the median values in each gender. The association of sarcopenic obesity both with the annual rate of decline in estimated GFR and a >30% decline in estimated GFR was evaluated using multivariate linear regression models and Cox proportional hazard models, respectively.

RESULTS

Participants with sarcopenic obesity were at an increased risk of a high annual rate of decline in estimated GFR, even after adjustment for the confounding variables (standardized β = -0.228, P <0.001). Sarcopenic obesity was also significantly associated with risk of a >30% decline in estimated GFR (hazard ratio 4.52, 95% CI 2.16-9.47; P < 0.01) in multivariate model.

CONCLUSIONS

Sarcopenic obesity evaluated by dual energy X-ray absorptiometry is associated with a faster decline in renal function in people with type 2 diabetes.

THE ASSOCIATION BETWEEN SENSE OF PURPOSE IN LIFE AND REPEATED MEASURES OF HEALTH BEHAVIORS OVER TIME

Although a stronger sense of purpose in life has been associated with reduced risk of chronic conditions and mortality, potential pathways underlying these associations remain understudied. In the present study, we tested if a higher baseline sense of purpose in life was associated with maintenance of recommended levels of five health behaviors. Prospective data included 13,771 adults from the Health and Retirement Study, who were assessed up to six times across an average of 9 years. In mixed models that adjusted for sociodemographic factors, those in the highest quartile of purpose, compared to those in the lowest quartile, had a higher likelihood of not smoking (RR=1.04; 95% CI: 1.03–1.06), remaining physically active (RR=1.42; 95% CI: 1.33–1.51), drinking moderate amounts of alcohol (RR=1.21; 95% CI: 1.13–1.29), not suffering from sleep problems (RR=1.29; 95% CI: 1.24–1.34), and maintaining healthy BMI (RR=1.09; 95% CI: 1.06–1.11) over follow-up.

Long-Term Associations Between Disaster Experiences and Cardiometabolic Risk: A Natural Experiment From the 2011 Great East Japan Earthquake and Tsunami

We investigated the association between disaster experience and the cardiometabolic risk of survivors 2.5 years after disaster onset, adjusting for health information predating the disaster, using natural experiment data stemming from the 2011 Great East Japan Earthquake and Tsunami. We used data from a cohort of adults aged 65 years or older in Iwanuma City, Japan, located 80 km (128 miles) west of the earthquake epicenter. The baseline survey was completed 7 months before the disaster, and the follow-up survey was performed among survivors approximately 2.5 years after the disaster. The survey data were linked to medical records with information on objectively measured cardiometabolic risk factors (n = 1,195). The exposure of interest was traumatic disaster experiences (i.e., housing damage and loss of loved ones). Fixed-effects regression showed that complete housing destruction was significantly associated with a 0.81-unit greater change in body mass index (weight (kg)/height (m)2; 95% confidence interval (CI): 0.24, 1.38), a 4.26-cm greater change in waist circumference (95% CI: 1.12, 7.41), and a 4.77-mg/dL lower change in high-density lipoprotein cholesterol level (95% CI: -7.96, -1.58) as compared with no housing damage. We also observed a significant association between major housing damage and decreased systolic blood pressure. Continued health checkups and supports for victims who lost homes should be considered to maintain their cardiometabolic health.

Income-based inequalities in caregiving time and depressive symptoms among older family caregivers under the Japanese long-term care insurance system: A cross-sectional analysis

AIM

Long-term care systems may alleviate caregiver burdens, particularly for those with fewer resources. However, it remains unclear whether socioeconomic disparity in caregiver burdens exists under a public, universal long-term care insurance (LTCI) system. This study examined income-based inequalities in caregiving time and depressive symptoms in Japanese older family caregivers. We further compared inequality in depressive symptoms with that of non-caregivers to evaluate whether family caregiving exacerbates this disparity.

METHODS

Data were obtained from a cross-sectional, nationwide survey conducted by the Japan Gerontological Evaluation Study in 2013. Participants were functionally independent older adults aged ≥65 years (N = 21,584). Depressive symptoms were assessed using the Geriatrics Depression Scale (GDS); caregiving hours per week, household income, and other covariates were also assessed.

RESULTS

Family caregivers occupied 8.3% of the total. A Poisson regression model revealed that caregivers in lower income groups (compared to those in the highest) were 1.32 to 1.95 and 1.63 to 2.68 times more likely to engage in ≥36 and ≥72 hours/week of caregiving, respectively. As for the GDS (≥5), an excess risk was found in the caregivers in lower (compared to higher) income groups (adjusted prevalence ratio: 1.57-3.10). However, an interaction effect of income by caregiving role indicated no significant difference in inequality between caregivers and non-caregivers (p = .603). The excess risk for GDS (≥5) in the caregivers compared to non-caregivers was observed across income groups.

CONCLUSIONS

Our findings revealed a possible disparity in family caregivers under the public LTCI system. Further studies should examine factors associated with longer caregiving hours in lower income households. Our findings also suggest the necessity for more efforts to alleviate depressive symptoms in family caregivers under the LTCI system regardless of income level, rather than exclusively supporting those with a low income.

Deposition of a titania layer on spherical porous silica particles and their nanostructure-induced vapor sensing properties

A titania-stearic acid hybrid layer was deposited onto well-defined silica-hexadecyltrimethylammonium hybrid spherical particles with 854 nm size to obtain nanoporous particles with a useful hierarchical core-shell structure. The deposition of a 35 nm-thick titania layer was confirmed by transmission electron microscopy. The core-shell particles were washed with acidic ethanol (solvent extraction) and calcined at 550 °C for 5 h to remove the template, resulting in the formation of nanoporous titania coated nanoporous silica spherical particles, which have a bimodal pore size distribution attributed to the hierarchical porous core and porous shell structure. The nanoporous titania coated particles exhibited an unusual crystal phase transition; only anatase was present even after the calcination at 1000 °C for 1 h. This would be due to the interfacial bonding between the core silica and the shell titania, preventing the crystal phase transition from anatase to rutile. On the other hand, the direct calcination of the titania-stearic acid coated particles without solvent extraction led to a shell composed of both anatase and rutile. The transformation to rutile could be caused by the strong exothermic reaction during the oxidative decomposition of the occluded stearic acid. Furthermore, the intense exothermic reaction induced the formation of a yolk-shell structure, which played a role in the sensitive/selective sensing properties for acetic acid when the yolk-shell particles were coated onto a nanomechanical Membrane-type Surface stress Sensor (MSS).

Retirement and mental health: dose social participation mitigate the association? A fixed-effects longitudinal analysis

Background

Empirical evidence investigating heterogeneous impact of retirement on mental health depending on social backgrounds is lacking, especially among older adults.

Methods

We examined the impact of changes in working status on changes in mental health using Japanese community-dwelling adults aged ≥65 years participating in the Japan Gerontological Evaluation Study between 2010 and 2013 (N = 62,438). Between-waves changes in working status (“Kept working”, “Retired”, “Started work”, or “Continuously retired”) were used to predict changes in depressive symptoms measured by the Geriatric Depression Scale. First-difference regression models were stratified by gender, controlling for changes in time-varying confounding actors including equivalised household income, marital status, instrumental activities of daily living, incidence of serious illnesses and family caregiving. We then examined the interactions between changes in working status and occupational class, changes in marital status, and post-retirement social participation.

Results

Participants who transitioned to retirement reported significantly increased depressive symptoms (β = 0.33, 95% CI: 0.21–0.45 for men, and β = 0.29, 95% CI: 0.13–0.45 for women) compared to those who kept working. Men who were continuously retired reported increased depressive symptoms (β = 0.13, 95% CI: 0.05–0.20), whereas males who started work reported decreased depressive symptoms (β = −0.20, 95% CI: -0.38–-0.02). Men from lower occupational class (compared to men from higher class) reported more increase in depressive symptoms when continuously retired (β = −0.16, 95% CI: -0.25–-0.08). Those reporting recreational social participation after retirement appeared to be less influenced by transition to retirement.

Conclusions

Retirement may increase depressive symptoms among Japanese older adults, particularly men from lower occupational class backgrounds. Encouraging recreational social participation may mitigate the adverse effects of retirement on mental health of Japanese older men.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4427-0) contains supplementary material, which is available to authorized users.