Social participation and functional disability trajectories in the last three years of life: The Japan Gerontological Evaluation Study

BACKGROUND

Functional disability has various patterns from onset until death. Although social participation is a known protective factor against functional disability among older individuals, it is unclear whether social participation is associated with the trajectory patterns of functional disability prior to death. This study assessed the association between social participation, specifically in horizontal and vertical groups, and the trajectories of functional disability prior to death.

METHODS

We used survey data from the 2010 Japan Gerontological Evaluation Study for functionally independent older adults combined with public long-term care insurance system data from 2010 to 2016 (n = 4,502). The outcome variables included five previously identified trajectory patterns using group-based trajectory modeling. As the explanatory variable, we used three definitions of social participation: any group, horizontal group (e.g., sports, hobbies), or vertical group (e.g., political, religious), at least once a month. We used a multinomial logistic regression analysis to calculate odds ratios with 95 % confidence intervals for the identified trajectory patterns.

RESULTS

Participation in any groups was significantly less likely to belong to "Accelerated disability" (OR=0.74 [95 % CIs 0.60-0.92]), "Persistently mild disability" (0.68 [0.55-0.84]), and "Persistently severe disability" (0.67 [0.50-0.83]) compared to "Minimum disability." Although participation in horizontal groups was similarly associated with trajectories regardless of gender, vertical groups was not associated with trajectories among males.

CONCLUSIONS

Social participation among older adults may be associated with an extended period of living without disabilities before death. This association may differ by gender and social participation group and requires further research.

Differences in prevalence of self-reported oral hypofunction between older adult patients with rheumatoid arthritis and the general older population: A cross-sectional study using propensity score matching

OBJECTIVE

To examine the association between rheumatoid arthritis (RA) and oral hypofunction (OHF) using propensity score matching (PSM) to adjust for differences between older adults with RA and the general older adult population.

METHODS

We conducted a cross-sectional survey among 189 older adults with RA in 2019 (mean age, 71.9 ± 3.6) and 47 178 independent older adult residents in 2016 (mean age, 71.6 ± 4.0), respectively. The questionnaire covered information on socio-demographic characteristics and OHF for both groups. Age, sex, educational level and smoking history were used to determine PSM. Prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported OHF (fewer remaining teeth, decreased masticatory function, deterioration of swallowing function and oral dryness) were estimated using Poisson regressions.

RESULT

OHF was observed in 44.4% of patients with RA and 27.5% of residents. Before PSM, the prevalence of OHF among patients with RA was higher than that of residents (PR, 1.75; 95% CI, 1.50-2.05). After PSM, there were 189 patients with RA and residents, and the prevalence of OHF among patients with RA was still higher (PR, 1.61; 95% CI, 1.22-2.13). Poisson regression showed that the prevalence of 19 or fewer teeth (PR, 1.06; 95% CI, 0.82-1.36), difficulties eating tough foods (PR, 1.18; 95% CI, 0.90-1.55), difficulties swallowing tea or soup (PR, 1.77; 95% CI, 1.19-2.63), and dry mouth (PR, 2.79; 95% CI, 1.90-4.07) was higher among patients with RA than residents.

CONCLUSION

Compared with the general older adult population, patients with RA have a higher prevalence of self-reported OHF.

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.

Association among the number of teeth, dental prosthesis use, and subjective happiness: A cross-sectional study from the Japan Gerontological Evaluation study (JAGES)

STATEMENT OF PROBLEM

Little is known about the association between the number of teeth and self-rated happiness or the association between dental prosthesis use and self-rated happiness in an older population.

PURPOSE

The purpose of this cross-sectional study was to examine the association between the number remaining of teeth with and without dental prosthesis use and self-rated happiness in an older population.

MATERIAL AND METHODS

The survey data from the 2016 Japan Gerontological Evaluation Study (JAGES) on independent participants aged 65 years or older were assessed. The Poisson regression and multiple imputation methods were used for analyses. Covariates were age, sex, marital status, educational attainment, self-rated health, self-rated economic situation, and symptoms of depression.

RESULTS

The data from 178 090 participants, 81 489 men (45.8%) and 96 601 women (54.2%), were analyzed, with a mean ±standard deviation age of 73.6 ±6.1 years. Overall, 66.4% of the participants were happy, declining to 45.7% in those who had 0 to 9 teeth and no dental prosthesis (n=3102). It was 61.5% in those who had 0 to 9 teeth and used a dental prosthesis (n=41 424), 56.8% in those who had 10 to 19 teeth and no dental prosthesis (n=6719), 65% in those who had 10 to 19 teeth and used a dental prosthesis (n=31 592), 70.5% in those who had ≥20 teeth and no dental prosthesis (n=52 525), and 70.1% in those who had ≥20 teeth and used a dental prosthesis (n=42 728). The interaction analysis showed that the reduction in the probability of being happy among those with fewer teeth was smaller among those who used a dental prosthesis.

CONCLUSIONS

Having a higher number of teeth and using a dental prosthesis were independently associated with being happy. A significant interaction suggested that dental prosthesis use improves happiness among those with moderate to severe tooth loss (<20 remaining teeth).

Socioeconomic Status Transition Throughout Life and Risk of Dementia

Importance

Socioeconomic status (SES) is associated with dementia. However, the role of SES transitions in dementia is less explored; such evidence would be useful to understand whether social mobility is associated with healthy longevity at older ages.

Objective

To investigate the association of lifetime SES transition with risk of dementia.

Design, Setting, and Participants

This prospective cohort study, conducted from August 2010 to December 2016, used data from the Japan Gerontological Evaluation Study for participants aged 65 years or older from 31 different areas in Japan. Individuals with missing SES values, loss of follow-up, or new dementia onset 1 year or less from baseline were excluded. Data analysis was performed from April 2022 to April 2023.

Exposure

Transitions in SES across the life course.

Main Outcomes and Measures

The main outcome was risk of dementia incidence and corresponding loss or gain of dementia-free periods in a lifespan. The incidence of dementia was identified with a national registry of long-term nursing care services.

Results

A total of 9186 participants (4703 men [51.2%]) were included. The mean (SD) age at baseline was 74.2 (6.0) years. Six SES transitions were identified: upward, stable-high, upper-middle, lower-middle, downward, and stable-low. During the follow-up period, 800 cases of dementia were identified. Many dementia risk factors, including lifestyle behaviors, comorbidities, and social factors, were associated with SES transition patterns. Compared with lower-middle SES, the lowest risk of dementia was observed for upward transition (hazard ratio [HR], 0.66; 95% CI, 0.57-0.74) followed by stable-high (HR, 0.77; 95% CI, 0.69-0.86), downward (HR, 1.15; 95% CI, 1.09-1.23), and stable-low (HR 1.45; 95% CI, 1.31-1.61) transition (P <  .001 for linearity); there was no association of upper-middle transition with risk of dementia (HR, 0.91; 95% CI, 0.79-1.03). The greatest increases in dementia-free years in the lifespan were also associated with upward SES transition (eg, 1.8 years [95% CI, 1.4-2.2 years] at age 65 years), while the downward transition was associated with the largest loss in lifetime dementia-free years at 75 years or older (eg, -1.4 years [95% CI, -2.4 to -0.4 years] at age 85 years).

Conclusions and Relevance

This cohort study of Japanese older adults identified that upward and downward SES transitions were associated with risk of dementia and the length of dementia-free periods over the lifespan. The results may be useful to understand the association between social mobility and healthy longevity.

[A framework for promoting and evaluating "Kayoi-no-ba" initiatives according to the Plan-Do-Check-Action cycle: The ACT-RECIPE framework]

Objective　In 2019, the Ministry of Health, Labour and Welfare emphasized the importance of promoting "Kayoi-no-ba" (or "places to go") initiatives according to the Plan-Do-Check-Action (PDCA) cycle. However, it proposed no specific promotion measures or standardized evaluation frameworks. This study is intended to propose a framework for local government officials to promote and evaluate "Kayoi-no-ba" initiatives according to the PDCA cycle.Methods　The working group (WG) conducted a narrative review of research and extracted evaluation models and indicators that could be used to create the framework. The co-researcher review committee discussed a draft framework prepared by the WG, and the WG revised it based on the discussion; this process was repeated four times. Using the completed framework, we calculated the score of the "Kayoi-no-ba" initiatives in 50 Tokyo municipalities and conducted regional correlation analyses on the relationship between the score of the "Kayoi-no-ba" initiatives in 50 Tokyo municipalities and the number of "Kayoi-no-ba" per 1,000 older persons.Results　The completed framework (named "ACT-RECIPE" by rearranging the underlined characters below) comprised the following six evaluation phases: (1) Comprehension: understanding the key lessons around disability and frailty prevention, and the necessity for "Kayoi-no-ba"; (2) Research and Planning: clarifying the current status of "Kayoi-no-ba," the strengths of the community, and the issues to be addressed through a community assessment, and developing a plan to resolve the issues; (3) Team Building and Collaboration: building a team by collaborating with organizations to solve problems; (4) Implementation: implementing the initiatives necessary to solve problems; (5) Evaluation: verifying changes in output and outcome indicators from the initiatives; and (6) Adjustment and Improvement: re-examining plans, teams, content, and goals based on the evaluation results. In these six phases, we designated 10 core items and accompanying subitems. The median score rate of the ACT-RECIPE framework in 50 municipalities was 75% for "Comprehension," 61% for "Research and Planning," 69% for "Team Building and Collaboration," 64% for "Implementation," 31% for "Evaluation," and 56% for "Adjustment and Improvement," and the mean ACT-RECIPE score rate was 57%. A significant positive correlation (rs=0.43, P=0.002) was observed between the ACT-RECIPE mean score rate and the number of "Kayoi-no-ba" per 1,000 older persons.Conclusion　We proposed the ACT-RECIPE as a framework for promoting and evaluating "Kayoi-no-ba" initiatives according to the PDCA cycle. We hope that this framework will lead to further progress in "Kayoi-no-ba" initiatives and facilitate evaluation of their effectiveness according to the PDCA cycle.

The Purpose of Internet Use and Face-To-Face Communication With Friends and Acquaintances Among Older Adults: A JAGES Longitudinal Study

Internet use influences social interactions in society. However, there is no consensus on whether and what kind of Internet use increases face-to-face communication (FFC). This study investigated the mode of Internet use that increases FFC among older adults after three years. Participants were 8734 adults aged 65 or older who responded to the Japan Gerontological Evaluation Study (JAGES) surveys in 2016 and 2019. The exposures were the purposes of Internet use in 2016. The outcome was the frequency of FFC with friends or acquaintances in 2019. The confounders included 13 demographic, socioeconomic, and psychological variables. We performed modified Poisson regression analyses and found that Internet use for communication in 2016 increased FFC in 2019, especially for low-frequency FFC in 2016. Internet-based non-FFC may help promote FFC and prevent social isolation among older adults who are less likely to interact with others.

Community-level group sports participation and all-cause, cardiovascular disease, and cancer mortality: a 7-year longitudinal study

BACKGROUND

Community-level group sports participation is a structural aspect of social capital that can potentially impact individual health in a contextual manner. This study aimed to investigate contextual relationship between the community-level prevalence of group sports participation and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in older adults.

METHODS

In this 7-year longitudinal cohort study, data from the Japan Gerontological Evaluation Study, a nationwide survey encompassing 43,088 functionally independent older adults residing in 311 communities, were used. Cause of death data were derived from the Japanese governmental agency, The Ministry of Health, Labour and Welfare, for secondary use. "Participation" was defined as engaging in group sports for one or more days per month. To analyze the data, a two-level survival analysis was employed, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Among the participants, 5,711 (13.3%) deaths were identified, with 1,311 related to CVD and 2,349 to cancer. The average group sports participation rate was 28.3% (range, 10.0-52.7%). After adjusting for individual-level group sports participation and potential confounders, a higher community-level group sports participation rate was found to be significantly associated with a lower risk of both all-cause mortality (HR: 0.89, 95% CI: 0.83-0.95) and cancer mortality (HR: 0.89, 95% CI: 0.81-0.98) for every 10% point increase in the participation rate. For CVD mortality, the association became less significant in the model adjusted for all covariates (HR: 0.94, 95% CI: 0.82-1.09).

CONCLUSIONS

Our findings support the existence of a preventive relationship between community-level group sports participation and the occurrence of all-cause and cancer mortality among older individuals. Promoting group sports within communities holds promise as an effective population-based strategy for extending life expectancy, regardless of individual participation in these groups.

Regional Inequalities in Oral Frailty and Social Capital

INTRODUCTION

Oral frailty leads to poor nutritional status, which, in turn, leads to frailty. This cross-sectional study aimed to determine regional differences in the prevalence of oral frailty and to identify factors associated with oral frailty using 3-level multilevel models.

METHODS

This study comprised 165,164 participants aged ≥65 y without long-term care requirements in the Japan Gerontological Evaluation Study. The dependent variable was oral frailty, which was calculated based on age, number of teeth, difficulty in eating tough foods, and choking. The individual-level independent variables included sociodemographics, present illness, social participation, frequency of meeting friends, and social capital. The local district-level independent variable was social capital (n = 1,008) derived from exploratory factor analyses. The municipality-level independent variable was population density (n = 62). Three-level multilevel Poisson regression analysis was performed to calculate the prevalence ratios (PRs).

RESULTS

The prevalence of oral frailty in municipalities ranged from 39.9% to 77.6%. Regarding district-level factors, higher civic participation was significantly associated with a lower probability of oral frailty. At the municipality level, the PR of the rural-agricultural area was 1.17 (95% confidence interval, 1.11-1.23) (reference: metropolitan).

CONCLUSION

These results highlight the usefulness of oral frailty prevention measures in encouraging social participation in rural areas.

KNOWLEDGE TRANSFER STATEMENT

The results of the present study showed regional differences in oral frailty. In particular, rural-agricultural areas show higher prevalence rates of oral frailty than those in metropolitan cities. Promoting measures of social participation among older adults may help prevent oral frailty in rural areas.

Profiles of central nervous system surgical site infections in endoscopic transnasal surgery exposing the intradural space

OBJECTIVE

Despite its efficacy and minimal invasiveness, the clean-contaminated nature of endoscopic transnasal surgery (ETS) may be susceptible to central nervous system surgical site infections (CNS-SSIs), especially when involving intradural exposure. However, the profiles of ETS-associated CNS-SSIs are not fully elucidated.

METHODS

The institutional ETS cases performed between May 2017 and March 2023 were retrospectively analysed. The incidences of CNS-SSIs were calculated, and their risk factors examined.

RESULTS

The incidence of CNS-SSIs was 2.3% (7/305) in the entire cohort and 5.0% (7/140) in ETSs with intradural exposure. All the CNS-SSIs were meningitis and developed following ETS with intradural exposure. The incidences were 0%, 5.6% and 5.8% in ETSs with Esposito grade 1, 2 and 3 intraoperative cerebrospinal fluid leakage, respectively. Among the pre- and intra-operative factors, body mass index (unit odds ratio (OR), 0.62; 95% confidence interval (CI), 0.44-0.89; P<0.01), serum albumin (unit OR, 0.03; 95% CI, 0.0007-0.92; P=0.02), and American Society of Anesthesiologists physical status score (unit OR, 20.7; 95% CI, 1.65-259; P<0.01) were significantly associated with CNS-SSIs. Moreover, postoperative cerebrospinal fluid leakage was also significantly associated with CNS-SSIs (OR, 18.4; 95% CI, 3.55-95.0; P<0.01).

CONCLUSIONS

The incidence of ETS-associated CNS-SSIs is acceptably low. Intradural exposure was a prerequisite for CNS-SSIs. Malnutrition and poor comorbidity status should be recognized as important risks for CNS-SSIs in ETS.

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.

Social disconnection and suicide mortality among Japanese older adults: A seven-year follow-up study

BACKGROUND

Few prospective studies have examined the association between social disconnection and late-life suicide. Therefore, we conducted a large-scale prospective study of older adults in Japan to examine differences in suicide mortality according to specific aspects of social disconnectedness.

METHODS

We conducted a nationwide baseline survey of functionally independent older adults (age ≥65 years) from 12 municipalities in Japan from 2010 to 2011. We followed the participants (n = 46,144) for cause of death through December 2017 using vital statistics. Social disconnection was assessed based on the indicators of eating alone, a lack of instrumental/emotional support, no participation in community activities, and no contact with friends. We adopted Cox regression models with multiple imputation for missing values and calculated the population-attributable fraction (PAF).

RESULTS

A total of 55 suicide deaths were recorded during an average follow-up of 7 years. Older adults with social disconnection had a marginally increased risk of suicide. The hazard ratio for eating alone vs. eating together was 2.81 (95% confidence interval [CI]: 1.47-5.37). The direction of these associations and point estimations did not largely change after controlling for depressive symptoms, an evident risk factor for suicidal behavior. The PAF indicated that eating alone was attributable to around 1800 (29%) of the suicide deaths among older adults annually in Japan.

CONCLUSION

Avoidance of not only depressive symptoms, but also social disconnection including eating alone, is useful in suicide prevention among older adults.

Living in public rental housing is healthier than private rental housing a 9-year cohort study from Japan Gerontological Evaluation Study

Housing tenure is an important aspect to determine health. However, even though renters tend to have more socioeconomic disadvantages than homeowners, mortality risk between private and public renters compared with homeowners remains unclear. Japanese public rented housing, such as the Urban Renaissance Agency, has been developed for supplying an adequate living environment since 1950s. This study aimed to examine the mortality risk among older Japanese residents living in private and public rented houses compared with those living in owner-occupied houses using 9-year follow-up data. This study drew upon a 9-year follow-up of participants in the Japan Gerontological Evaluation Study, a population-based cohort study of Japanese independent adults aged ≥ 65 years. Mortality from 2010 to 2019 was analyzed for 44,007 respondents. Housing tenure was defined by a questionnaire. Cox regression models were used for calculating the hazard ratio for mortality. Bonferroni correction was used to account for multiple testing between rental houses. Overall, 10,638 deaths occurred during the follow-up period. Compared with housing owners, all rental housing groups had a significantly higher risk of mortality. Among renters, participants who lived in public rental housing had the lowest risk of mortality even after adjusting for sociodemographic characteristics, health status, social status, and environmental status. Multiple testing among renters with Bonferroni correction showed that public renters had 0.80 times (95% CI 0.72-0.89) lower mortality risk than private renters. Although Japanese older adults living in public rental housing had a higher mortality risk than homeowners, this risk was lower than that among private renters. A positive neighborhood environment based on well-planned urban development may have contributed to this result. The results suggest that planned urban development lowers the risk of mortality in older renters in Japan.

Do changes in the frailty score differ by the type of group sports and exercises participated in? A 3-year longitudinal study

BACKGROUND

Older adults who engage in group sports and exercises achieve greater health benefits than those who exercise by themselves. The benefits of group participation may vary depending on the type of sports/exercise they engage in. The present study aimed to identify the association between specific sports and exercise types performed in groups and evaluate the longitudinal changes in multidimensional frailty scores among community-dwelling older adults in Japan.

METHODS

We used 3-year follow-up data from the Japan Gerontological Evaluation Study and analyzed 33,746 men and 36,799 women aged ≥ 65 years. To elucidate the relationship between participation in 20 types of group sports/exercises in 2016 (baseline) and the change in frailty score (using the Kihon Checklist, KCL) from 2016 to 2019, we performed linear regression analyses through multivariate adjustments for age group, self-rated health, marital status, living alone, occupational status, years of education, alcohol drinking status, smoking status, equivalent income, and disease status using an inverse probability weighting method. P < 0.05 was considered statistically significant.

RESULTS

The mean change in KCL scores over 3 years was + 0.62 and + 0.61 points in men and women, respectively, implying the degree of frailty worsened. The sports/exercise types that significantly prevented increments in KCL scores for both sexes compared to non-participants were hiking (men: B, - 0.36; women: B, - 0.29), walking (men: B, - 0.26; women: B, - 0.24), tennis (men: B, - 0.23; women: B, - 0.24), ground golf (men: B, - 0.21; women: B, - 0.19), and weight exercises (men: B, - 0.19; women: B, - 0.16).

CONCLUSION

Participation in specific sports and exercise groups offer significant physical and psychological benefits for frailty prevention among older adults in Japan. The results of this study may offer substantive evidence to encourage older adults to participate in group activities for the prevention of multidimensional frailty. It will also help public health stakeholders to decide which type of sports and exercise groups to promote in a community.

Sedentary behavior and the combination of physical activity associated with dementia, functional disability, and mortality: A cohort study of 90,471 older adults in Japan

OBJECTIVE

To examine the associations of sedentary behavior (SB) and the combination of moderate-to-vigorous intensity physical activity (MVPA) with dementia, functional disability, and mortality in older adults, and the heterogeneity in different subpopulations.

METHODS

Nation-wide cohort with 90,471 individuals aged ≥65 years in Japan. SB (<3, 3-<8, and ≥ 8 h per day [h/d]) and MVPA (0, 0 < MVPA<1, and ≥ 1 h/d) were measured in 2016. Long-term care registry-based incidence of outcomes was ascertained through 2021. Cox proportional hazard models were performed.

RESULTS

Compared with SB < 3 h/d group, SB ≥ 8 h/d was associated with higher risks of dementia, functional disability, and mortality with hazard ratios (95% confidence interval) of 1.36 (1.22-1.52), 1.32 (1.19-1.48), and 1.31 (1.18-1.45). The combination of MVPA and SB demonstrated a dose-respond trend of increasing risks of dementia, functional disability, and mortality with increased SB and decreased MVPA, where participants who spent no MVPA with SB ≥ 8 h/d had the highest risks. High MVPA attenuated but didn't eliminate the risks. Participants who spent MVPA≥1 h/d with SB ≥ 8 h/d had comparable risks to those who spent no MVPA with SB < 3 h/d. No heterogeneity was found by MVPA levels, sex, education, comorbidity, and depression conditions.

CONCLUSIONS

Prolonged daily SB was associated with higher risks of dementia, functional disability, and mortality in older adults, regardless of MVPA, sex, education, and chronic conditions. Individuals with high MVPA also face considerable risks when engaging in high SB. High MVPA with high SB revealed a comparable risk to no MVPA with low SB.

Does the neighborhood built and social environment reduce long-term care costs for Japanese older people? The JAGES2010-2019 cohort study

Japan's population has been aging steadily, evidenced by it spending JPY 11 trillion (USD 110 billion) on annual long-term care (LTC) costs in 2021. In this context, understanding the factors influencing LTC costs has become increasingly vital. Although studies have reported positive relationships between neighborhood environment and health outcomes, the connection between LTC costs and neighborhood environment remains unclear. To address this gap in the literature, this cohort study, conducted from 2010 to 2019 across seven Japanese municipalities and involving 34,982 older people, examined the relationship between eight neighborhood environment elements and the mean monthly cumulate costs (MMCC) of LTC. The results showed that older people who reported the presence of fresh food stores nearby and dangerous places for walking alone at night in the neighborhood had lower MMCC, by JPY 1,367.6 and 1,383.3 per month, respectively, than respondents who did not report the presence of these neighborhood elements. Meanwhile, older people whose neighborhoods had easily accessible facilities had higher MMCC of JPY 739.4. This study's key findings reveal significant relationships between neighborhood environment elements and LTC costs and can be used to support developments in urban design to support healthy aging and reduced LTC costs.

Comparison of the Incidence of Functional Disability Correlated With Social Participation Among Older Adults in Japan

BACKGROUND

Japan, which has the world's longest life expectancy, has been reporting rejuvenation of physical function among its older adult population. However, evidence for the incidence of functional disability is limited. This study aimed to investigate the comparison in the incidence of functional disability.

DESIGN

We used data from the Japan Gerontological Evaluation Study.

SETTING AND PARTICIPANTS

The participants were 2 nonoverlapping cohorts of 22,522 (2010-2013 cohort) and 26,284 (2016-2019 cohort) individuals aged 65 years and older from 5 municipalities who were followed for 3 years each.

METHODS

The incidence rates of functional disability during the 3-year follow-up period were compared between cohorts. To examine the incident differences between the cohorts, we adjusted for social participation and 9 additional factors that would be expected to improve with social participation using the Weibull survival models adjusting for municipalities as random effects. The analysis was stratified by age groups (65-74 years old and ≥75).

RESULTS

The incidence rate of functional disability per 10,000 person-years decreased from 68.6 (2010-2013 cohort) to 51.4 (2016-2019 cohort) in the 65 to 74 years old group and 380.0 (2010-2013 cohort) to 282.6 (2016-2019 cohort) in the ≥75 group; the hazard ratios (95% CIs) were 0.75 (0.64-0.89) and 0.73 (0.67-0.80), respectively. However, these significant decreases disappeared with adjustments for social participation and additional factors.

CONCLUSIONS AND IMPLICATIONS

The incidence of functional disability decreased in a recent cohort, which may be explained by social participation and possibly related factors. Promoting social participation could contribute to a decreasing incidence of functional disability among older adults.

Frequency of Going Outdoors and Risk of Poor Oral Health Among Older Japanese Adults: A Longitudinal Cohort From the Japan Gerontological Evaluation Study

BACKGROUND

The association between the frequency of going outdoors and the risk of poor oral health has been reported in several studies; however, the findings have been inconclusive.

METHODS

We conducted a 3-year longitudinal study of 19,972 Japanese adults aged ≥65 years who reported no poor oral condition at baseline in 2013. The respondents rated their frequency of going outdoors in three categories (≤1, 2-3, or ≥4 times/week), and the oral conditions reported in 2016 included tooth loss, chewing difficulty, swallowing difficulty, dry mouth, and composite outcomes. The associations between the frequency of going outdoors and the risk of poor oral health were examined as relative risk ratios (RRs) and 95% confidence intervals (CIs) using multivariable Poisson regression, while mediation analysis was performed to investigate indirect effects.

RESULTS

During the follow-up, 32.5% of participants developed poor oral health. In the mediation analysis, indirect effects were observed through low instrumental activities of daily living, depressive symptoms, little social network diversity, and underweight. Compared to going outdoors ≥4 times/week, the multivariable RRs of composite poor oral health conditions were 1.12 (95% CI, 1.05-1.20) for 2-3 times/week and 1.22 (95% CI, 1.07-1.39) for ≤1 time/week (P-trend < 0.001). Similar associations were observed for tooth loss, chewing difficulty, and swallowing difficulty; the corresponding RRs were 1.07 (95% CI, 0.97-1.19) and 1.36 (95% CI, 1.13-1.64) (P-trend = 0.002), 1.18 (95% CI, 1.06-1.32) and 1.30 (95% CI, 1.05-1.60) (P-trend < 0.001), and 1.15 (95% CI, 1.01-1.31) and 1.38 (95% CI, 1.08-1.77) (P-trend = 0.002), respectively.

CONCLUSION

The frequency of going outdoors was inversely associated with the risk of poor oral health through several modifiable risk factors in the older population.

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.

Socioeconomic status and incident depressive symptoms among older adults: A 3-year longitudinal study from the Japan Gerontological Evaluation Study

OBJECTIVES

The association between socioeconomic status (SES) and the onset of depressive symptoms has attracted considerable attention. However, few studies have simultaneously examined the association of multiple SES indicators, including "assets," with the onset of depressive symptoms. Therefore, this study examined the association of four SES indicators in old age ('years of education' 'equivalent income,' 'equivalent assets,' and 'the longest-held job') with new-onset depressive symptoms in a large Japanese dataset.

METHODS

This longitudinal study used panel data of cognitively and physically independent older adults from the Japan Gerontological Evaluation Study (JAGES) conducted in 2013 and 2016. Multivariate logistic regression analysis was conducted to examine the association of each SES indicator with new-onset depressive symptoms, and odds ratios and 95% confidence intervals (CIs) were calculated.

RESULTS

We analyzed the data of 40,257 older adults, with a mean age (± standard deviation) of 72.9 (±5.5) years. In the follow-up survey, 4292 older adults had new-onset depression symptoms (10.7%). 39.3% had 10-12 years of education. 36.9% had an equivalent income of up to JPY 1.99 million. 24.4% had equivalent assets of JPY 4-17.99 million. Most had a clerical job for the long time. Furthermore, fewer years of education (males: OR = 1.42, 95% CI = 1.22-1.64, p-value <0.001/females: 1.26, [1.09-1.47], p = 0.002), lower income (males: 1.64, [1.34-2.01], p < 0.001/females: 1.82, [1.49-2.22], p < 0.001), and fewer assets (males: 1.40, [1.16-1.68], p < 0.001/females: 1.21, [1.02-1.42], p = 0.025) resulted in higher odds of having new-onset depressive symptoms, even when other SES indicators were entered simultaneously.

CONCLUSIONS

All four SES indicators have an independent association with the development of new-onset depressive symptoms among older adults, reflecting different aspects of SES. The association between the "longest-held job" and new-onset depressive symptoms can be largely explained by other SES indicators. A multifaceted and lifetime approach is required to prevent the onset of depressive symptoms in old age.

Estimating Health Expectancy in Japanese Communities Using Mortality Rate and Disability Prevalence

Introduction

Although mortality and disability are known to be associated with health expectancy (LE), few studies have assessed the extent to which a reduction in their prevalence can extend a person's LE. Moreover, differences in this relationship based on gender have not been established. Thus, in this study, we constructed a regression model using the rate of mortality and prevalence of disability to predict LE in older adults (≥65 years) and assess the relationships between LE, mortality rate, and disability prevalence based on gender.

Methods

Data were collected from Japan's population registry and long-term insurance records (N = 344). Multiple linear regression was used to analyze the relationship between LE, mortality rate, and disability prevalence, stratified by gender.

Results

Age-adjusted mortality rate and disability prevalence significantly predicted LE and were significantly correlated with the measured LE index for both genders. For every 1% annual decrease in age-adjusted mortality, LE increased by 1.54 years for men and 2.15 years for women. Similarly, a 1% annual decrease in age-adjusted disability prevalence increased LE by 0.22 years for men and 0.32 years for women. The regression model coefficients indicated that the strength of the association between LE, mortality rate, and disability prevalence differed between genders. Our model accurately predicted LE (men: adjusted R2 = 0.968, women: adjusted R2 = 0.994).

Conclusions

Health promotion policies that are geared toward increasing health expectancy can be evaluated using mortality rate and disability prevalence as prognostic indicators. The strength of the association between LE, mortality, and disability differed between genders, suggesting the need for gender-specific policy planning to increase LE for both genders.

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.

Associations between older adults' going-out frequency and land price of neighbourhoods: Potency of land price as an indicator of homebound tendency

The aim of this study is to identify the potency of land price as a general indicator of the homebound tendency of neighbourhoods. For this purpose, we focus on the associations between land price and older adults' going-out frequency, while considering the similarities and differences from factors associated with walkability. The study targets are 19,270 individuals living in the Tokyo metropolitan area who are aged 65 years or older who are not certified as needing public long-term care insurance. This study uses a two-step procedure: a) the land price of each neighbourhood is estimated using rent price data from 2010 to 2019 collected by an official Japanese realtor organization; b) the associations between older adults' goingout frequency, according to the 2016 Japan Gerontological Evaluation Study, and the estimated land price of their neighbourhoods is identified using multilevel analysis. The results indicate that land price has strong negative associations with older adults' going-out frequency. Associations between land price or other walkability-associated factors, such as population density, ratio of commercial area, and proximity to the nearest train station, only appear when these factors and land price are included within the same model. The results suggest that, when inspecting homebound tendency in some neighbourhoods, factors relating to the built environment must be considered alongside land prices. Furthermore, the homebound status of older adults is a pressing challenge, especially in neighbourhoods with high land prices.

Family Pharmacy and Medication Adherence Among Older Adults in Japan: A Cross-Sectional Study of JAGES 2019

OBJECTIVES

Poor medication adherence among older adults is a global concern as it causes adverse drug interactions and inappropriate dosing. This study aimed to assess the association between family pharmacy and medication adherence among older adults.

METHODS

The Japan Gerontological Evaluation Study was a cross-sectional study of 18,792 people aged ≥65 years living in 61 municipalities in 25 prefectures who participated in a survey conducted in 2019 and did not require long-term care. Self-reported questionnaires were administered to evaluate whether the participants "always received medicines from the same pharmacy" and whether they had unused medicines. Modified Poisson regression was used to examine the association after adjusting for confounders.

RESULTS

Unused medicines were present in 89.9% of the "have group" (individuals who always received their medicines from the same pharmacy). This group had a lower prevalence of unused medicines (prevalence ratio [PR] = 0.87, 95% confidence interval [CI]: 0.82-0.92) than the "none group" (individuals who did not always receive their medicines from the same pharmacy). In the stratified analysis by education level, the prevalence of unused medicines was lower among those with low levels of education (≤9 years: PR = 0.82, 95% CI: 0.71-0.96; 10-12 years: PR = 0.81, 95% CI: 0.74-0.88).

DISCUSSION

Older adults who "always received medicines from the same pharmacy" had a lower prevalence of unused medicines, especially those with low levels of education. Thus, "always receiving medicines from the same pharmacy" may be effective in reducing the proportion of unused medicines and improving medication adherence.

Olfactory and taste dysfunctions caused by COVID-19: a nationwide study

BACKGROUND

Olfactory dysfunctions (OD) and taste dysfunctions (TD) are widely recognized as characteristic symptoms of COVID-19; however, the frequency and mode of occurrence has varied depending on the viral mutation. The prevalence and characteristics of OD/TD in Japan have not been definitively investigated. The purpose of this study is to assess the prevalence of OD/TD in Japan during the Alpha variant epidemic, and measure symptom prolongation at 6 months and 1 year later following initial infection.

METHODS

Patients treated for COVID-19 between February to May 2021 were evaluated for OD/TD symptoms and provided with a QOL questionnaire. Olfactory tests and taste tests were performed using Open Essence and Taste Strips, respectively.

RESULTS

Among the 251 COVID-19 patients who participated, 119 underwent both olfactory and taste tests. Prevalence of subjective OD and TD at the time of survey was 57.8% and 40.2%, respectively. After 12 months, the prevalence fell to 5.8% for OD and 3.5% for TD. Among the OD/TD patients, 36.6% experienced parosmia, and 55.4% experienced parageusia. Prevalence of parosmia and parageusia was higher at 6 and 12 months than at the time of survey. Patients with long-lasting disease reported qualitative dysfunctions and scored significantly higher in food-related QOL problems. Most patients who were aware of their hyposmia had low scores on the olfactory test (83.1%). In contrast, only 26.7% of patients who were aware of their hypogeusia had low scores on the taste test.

CONCLUSIONS

The prevalence of COVID-19-related OD and TD at the time of survey was 57.8% and 40.2%, respectively. Subjective symptoms of OD and TD persisted for one year in 5.8% and 3.5% of patients, respectively. More than half of the patients with OD or TD complained of qualitative dysfunction and a decrease in their QOL related to eating and drinking. Most patients with TD did not have true TD, but rather developed flavour disorders associated with OD. This conclusion is supported by the finding that patients with subjective OD had low scores on the olfactory test, whereas most patients with subjective TD had normal scores on the taste test.

Association of community-level social capital with dementia: A multilevel nine-year longitudinal study using data from the Japan Gerontological Evaluation Study

BACKGROUND

Individual-level social capital prevents cognitive decline. However, a few studies have focused on the effects of community-level social capital on dementia. Therefore, we investigated the association between community-level social capital and dementia onset based on longitudinal study data on older adults in Japan.

METHODS

We used longitudinal data from the Japan Gerontological Evaluation Study, obtained over nine years (2010-2019). In total, 35,921 physically and cognitively independent individuals (16,848 males and 19,073 females) aged ≥65 years and nested within 308 communities in seven municipalities participated in the study. Dementia onset was assessed using the public long-term care insurance registration. Social capital was assessed using three dimensions: civic participation, social cohesion, and reciprocity. We performed a two-level multilevel survival analysis stratified by sex, calculated hazard ratios (HRs), and 95% confidence intervals (CIs).

RESULTS

During the follow-up, 6245 (17.4%) dementia onset cases were identified. The cumulative incidence of dementia was 16.2% in males and 18.4% in females. After adjusting for covariates, individual-level civic participation was associated with a lower incidence of dementia in both males and females (HR, 0.84; 95% CI, 0.77-0.92; HR, 0.78; 95% CI, 0.73-0.84). Community-level civic participation and social cohesion were associated with a lower incidence of dementia among females (HR, 0.96; 95% CI, 0.93-0.99; HR, 0.93; 95% CI, 0.88-0.98) and cross-level interaction on social cohesion among females (HR, 0.95; 95% CI, 0.90-0.99).

CONCLUSIONS

Living in a community with high civic participation and social cohesion is associated with a lower incidence of dementia among older females. Therefore, promoting civic participation and social cohesion in the community may be a useful population-based strategy to delay or prevent the onset of dementia.

Laminar-type gratings overcoated with carbon-based materials to enhance analytical sensitivity of flat-field emission spectrograph in the VUV region

Laminar-type spherical diffraction gratings overcoated with carbon-based materials were designed, fabricated, and evaluated for the purpose of enhancing the analytical sensitivity of the flat-field spectrograph in a vacuum ultraviolet region of 35-110 eV. As the design benchmark for numerical calculations, diffraction efficiency (DE) and spectral flux, which are defined by the product of the DE and numerical aperture and correlate with the analytical sensitivity of the spectrograph, were used. To simplify the feasibility study on the overcoating effects, we assumed a laminar-type grating having a grating constant of 1/1000 mm and coated with a Au layer of 30.0 nm thickness and an incidence angle of 84.0°. The optimized groove depth and duty ratio were 30.0 nm and 0.3, respectively. In addition, the optimum thicknesses of the overcoating layer were 44, 46, 24, and 30 nm for B4C, C, diamond-like-carbon, and SiC, respectively. Based on these results, we have fabricated a varied-line-spacing holographic grating overcoated with B4C with a thickness of 47 nm. For the experimental evaluation, we used the light source of Mg-L and Al-L emissions excited by the electron beam generated from an electron microscope, an objective flat-field spectrograph, and a CCD imaging detector. The experimental results showed that the spectrograph employing a new grating overcoated with the B4C layer indicated almost the same spectral resolution and 2.9-4.2 times higher analytical sensitivity compared with those obtained with a previously designed Au-coated grating having a grating constant of 1/1200 mm and used at an incidence of 86.0°.

Association between hearing status and social participation in Japanese older adults: A cross-sectional study from the Japan gerontological evaluation study

PURPOSE

Hearing is known to decline with age. As sensitivity to speech declines, conversation becomes more difficult and social interactions are affected, resulting in increased risk of cognitive decline. This study aimed to examine the relationship between hearing status and social participation.

MATERIALS AND METHODS

The study included 21,117 adults aged 65 years or older who responded to a survey in 2019. The survey asked participants about their hearing status and how frequently they participated in certain social activities.

RESULTS

The analysis of the relationship between degree of hearing and social activity showed lower hearing status odds ratios for those who participated more frequently in social activities compared to those who participated less frequently. The odds ratios were as follows, hobby clubs (OR 0.81, 95%CI 0.78-0.84), activities such as teaching skills or passing on experiences to others (OR 0.69, 95%CI 0.65-0.75), and meeting with friends (OR 0.77, 95%CI 0.74-0.79). Compared to those who did not participate in social activities, those who participated in three or more types of groups had significantly lower hearing impairment (OR 0.75, 95% CI 0.72-0.79).

CONCLUSION

Hearing impairment was shown to inhibit participation in activities, including those that require communication with multiple people or smooth communication, those that involve a wide range of ages, and those that involve work and movement. Hearing impairment should be identified and addressed in its early stages to prevent its negative impact on social participation.

Association between dietary pattern and insomnia symptoms among independent older adults: A cross-sectional study based on JAGES

BACKGROUND

Poor diet can cause sleep disorders; however, this association has not been established in older populations. This study investigated the association between dietary patterns and insomnia symptoms in independent older adults.

METHODS

This cross-sectional study targeted independent older Japanese adults aged ≥74 years. We used insomnia symptoms classified into three domains: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and insomnia. These symptoms were assessed as dependent variables by a self-reported questionnaire. Dietary patterns (DP), identified by principal component analysis of a self-administered diet history questionnaire, were used as independent variables. Poisson regression analysis was used to estimate the prevalence ratios and 95% confidence intervals with adjustment for potential confounders.

RESULTS

Among 1,311 participants (mean age = 80.1; women, 48.5%), we identified three dietary patterns: DP1 was characterized by a high intake of vegetables, soy products, and fruits and a low intake of rice; DP2 was characterized by a high intake of fish, chicken, processed meat, and noodles and a low intake of soy products; and DP3 was characterized by a lower intake of fruits and confectionaries. Higher DP1 scores were significantly associated with a lower prevalence of DIS (p-for-trend = 0.012). A higher DP2 score was significantly associated with a higher prevalence of insomnia (p-for-trend = 0.032). There was no significant association between DP3 and insomnia symptoms (p-for-trend >0.05).

CONCLUSION

Our results highlighted that a dietary pattern with a high intake of vegetables, soy products, and fruits may contribute to reducing insomnia symptoms among independent older adults.

Does eating with others promote happiness among older adults living alone? A 3-year longitudinal study of the Japan gerontological evaluation study

OBJECTIVE

Living a happy life is an essential issue for old adults. However, how eating with others contributes to happiness and whether this association is different by living arrangements or not is unknown. The current study examined the relationship between the frequency of eating with others and happiness among older adults according to their living arrangements using 3-year longitudinal data.

METHODS

The analyzed sample comprised 18,727 people (10,920 males and 7807 females) with low happiness (0-7 points on score of 0-10 points) from Japan Gerontological Evaluation Study (JAGES) in 2016. Our exposure was the frequency of eating with others: rarely, a few times a year, a few times a month, and a few times a week or more. We performed Modified Poisson Regression to examine the association between the frequency of eating with others and high happiness (8-10 points) in 2019 stratified by living arrangement (living alone/with others).

RESULTS

A total of 4352 (23.2%) people showed high happiness in 2019. After adjusting for age, sex, marital status, education, household income, social participation, illnesses under treatment, and depressive symptoms in 2016, the cumulative incidence ratio (CIR) for high happiness in 2019 among people living alone was more significant, that is, 1.28 (95% confidence intervals: 0.88-1.87), 1.50 (1.05-2.14), and 1.82 (1.26-2.63), than 1.28 (1.11-1.48), 1.30 (1.12-1.50), and 1.33 (1.16-1.52) among people living with others for those who ate with others a few times a year, a few times a month, and a few times a week or more compared to those who rarely ate with others, respectively. The interaction between the frequency of eating with others and living arrangements was statistically significant. The trend test showed that higher frequency of eating with others was significantly associated with high happiness.

CONCLUSIONS

Eating with others was associated with improved happiness among older adults, with such an association being stronger among people living alone.

Lower socio-economic status in adolescence is associated with poor oral health at an older age: Mediation by social and behavioural factors

AIM

To examine the mediators between lower socio-economic status (SES) in adolescence and oral health at an older age to uncover the underlying mechanisms of the association.

METHODS

Participants (n = 21 536) aged ≥65 years from the Japan Gerontological Evaluation Study were evaluated. The dependent variables were self-rated chewing difficulty and having ≤19 remaining teeth. The main independent variable was self-perceived SES in adolescence. The Karlson-Holm-Breen method was used for mediation analysis.

RESULTS

Mean age of the participants was 74.8 years (standard deviation = 6.4), and 51.5% were female. Overall, 5598 (26.0%) participants reported chewing difficulty and 9404 (43.7%) had ≤19 remaining teeth. Lower SES in adolescence was associated with a higher prevalence of chewing difficulty (odds ratio [OR] = 1.38, 95%confidence interval [CI] = 1.29-1.48; total effect). After controlling for mediators, OR for lower SES in adolescence was 1.22 (95%CI = 1.13-1.30; direct effect) and 1.13 (95%CI = 1.11-1.16; indirect effect). Mediators, prominently the number of teeth and income, explained 39.3% of the associations. Lower SES in adolescence increased the odds of ≤19 remaining teeth by OR = 1.23 (95% CI = 1.16-1.31; total effect). After controlling for mediators, the OR for lower SES in adolescence was 1.03 (95%CI = 0.97-1.10; direct effect) and 1.19 (95%CI = 1.16-1.23; indirect effect). Mediators, prominently educational attainment, explained 85.0% of the associations.

CONCLUSIONS

Lower SES in adolescence was associated with poor oral health at an older age through mediators. Approaches that consider social determinants from the beginning of the life course are required.

Cooking skills, living alone, and mortality: JAGES cohort study

BACKGROUND

Living alone without someone to cook meals for them can happen more frequently in aging due to bereavement, divorce, or other family changes. Health risks to older adults due to poor cooking skills may be more pronounced among those living alone. We aimed to examine whether cooking skills are associated with mortality according to cohabitation status in older Japanese people.

METHODS

Participants in the Japan Gerontological Evaluation Study, a population-based cohort of independent older adults, were followed for three years (n = 10,647). Cooking skill was assessed using a scale with good validity and modified for Japanese people in the baseline survey. After stratification by living alone or together, participants with high and low cooking skills were matched on demographic, socioeconomic, health-related factors, and availability of food stores using propensity score matching. All-cause mortality risks were compared between high and low cooking skills using Cox regression models.

RESULTS

During the follow-up, 520 of the 10,647 participants died. One hundred and seventy-one pairs of high and low cooking skills were matched among those living alone, and 2,161 pairs among those living with others were matched as well. The hazard ratio of the low level of cooking skills (vs. high) was 2.50 (95% confidence interval [CI]: 1.10-5.68) among those living alone, while 1.05 (95% CI: 0.82-1.33) among those living with others.

CONCLUSION

Lower cooking skills were associated with a higher risk of mortality only among those living alone. Cooking skills may be important for older adults who live alone to reduce mortality risk.

Community gender norms, mental health, and suicide ideation and attempts among older Japanese adults: a cross-sectional study

OBJECTIVES

Gender norms embedded in communities may restrict opportunities and harm the mental health of older adults, yet this phenomenon has received little attention. This study investigates the connection between older adults' perceptions of community gender norms and mental health and suicide-related outcomes.

DESIGN

Cross-sectional.

SETTING

This study analyzed data from the 2019 wave of the Japan Gerontological Evaluation Study.

PARTICIPANTS

In total, 25,937 participants aged 65 years or older in 61 municipalities.

MEASUREMENTS

Perceptions of community gender norms were assessed by the respondents' perceptions of the gender-differentiating language used by those around them such as "You should/should not do XXX, because you are a man/woman."

RESULTS

The prevalence of all mental health outcomes was higher among both men and women who perceived community gender norms as restrictive. These associations remained in fully adjusted multivariable analyses. Prevalence ratios for men were 1.36 [95% confidence interval: 1.13, 1.65] for psychological resistance to obtaining help, 1.85 [1.54, 2.23] for depressive symptoms, 1.99 [1.34, 2.96] for suicidal ideation, and 2.15 [1.21, 3.80] for suicide attempts. The corresponding figures for women were 1.39 [1.17, 1.65], 1.80 [1.55, 2.10], 2.13 [1.65, 2.74], 2.62 [1.78, 3.87]. There was a more pronounced association between perceiving community gender norms as restrictive and depressive symptoms and suicidal behaviors among those with nonconventional gender role attitudes compared to those with conventional attitudes.

CONCLUSIONS

Considering the effects of community gender norms, in addition to individual gender role attitudes, may be critical in designing effective public health interventions for improving mental health.

Dental prosthesis use is associated with higher protein intake among older adults with tooth loss

BACKGROUND

Tooth loss is associated with reduced protein intake, which leads to sarcopenia and frailty in older adults.

OBJECTIVE

To evaluate the protective effect of dental prostheses on decreased protein intake in older adults with tooth loss.

METHODS

This cross-sectional study was based on a self-reported questionnaire targeting older adults. Data were obtained from the Iwanuma Survey of the Japan Gerontological Evaluation Study. We used % energy intake (%E) of total protein as the outcome and the use of dental prostheses and number of remaining teeth as explanatory variables. We estimated the controlled direct effects of tooth loss by fixing the use/non-use of dental prostheses based on a causal mediation analysis, including possible confounders.

RESULTS

Among 2095 participants, the mean age was 81.1 years (1SD = 5.1), and 43.9% were men. The average protein intake was 17.4%E (1SD = 3.4) of the total energy intake. Among participants with ≥20, 10-19 and 0-9 remaining teeth, the average protein intake was 17.7%E, 17.2%E/17.4%E and 17.0%E/15.4%E (with/without a dental prosthesis), respectively. Compared to participants with ≥20 remaining teeth, those with 10-19 remaining teeth without a dental prosthesis did not have a significantly different total protein intake (p > .05). Among those with 0-9 remaining teeth without a dental prosthesis, total protein intake was significantly low (-2.31%, p < .001); however, the use of dental prostheses mitigated the association by 79.4% (p < .001).

CONCLUSION

Our results suggest that prosthodontic treatment could contribute to maintaining protein intake in older adults with severe tooth loss.

Do disasters exacerbate socioeconomic inequalities in health among older people?

Disasters can exacerbate socioeconomic health disparities because of differential exposure (e.g., socioeconomically disadvantaged groups are more likely to be exposed to disaster-related trauma) and differential vulnerability (disadvantaged groups are more likely to suffer health consequences of exposure to trauma). We sought to test whether health disparities among older adults widened in the area which was directly affected by the 2011 Great East Japan Earthquake & Tsunami compared to areas which largely escaped tsunami damage. We used data from a cohort of community-dwelling older adults who were directly affected by the 2011 disaster (the Iwanuma Study) and municipalities that were not directly affected (the JAGES parent cohort excluding Iwanuma city). The Iwanuma Study gathered pre-disaster information from participants in 2010 (seven months before the disaster) as well as post-disaster information in 2013, 2016 and 2019 (2.5, 5.5 and 8.5 years after the disaster). Our outcomes were depressive symptoms (GDS) and instrumental activities of daily living (IADL). We examined the pre- versus post-disaster trends in socioeconomic health disparities using the slope index and relative index of inequality. We then conducted a difference-in-difference analysis comparing the pre/post disaster change in health disparities in the "exposed" city (Iwanuma) compared to "control" cities. We found clear pre-disaster socioeconomic inequalities in both GDS and IADL in both the exposed and control cities. However, the magnitude of these inequalities did not change after the disaster on either the absolute or relative scales. The 2011 disaster in northeastern Japan did not exacerbate pre-existing patterns of health inequalities in the older population.

Moderating effect of country-level health determinants on the association between hobby engagement and mental health: cross-cohort multi-level models, meta-analyses, and meta-regressions

BACKGROUND

Theories from anthropology, evolutionary psychology, and sociology have focused on the potential adaptive benefits of hobby engagement for mental health in older adults. However, previous studies have used data from single countries, potentially biased by specific measurement and methodological approaches, cohort effects, or cultural specificities. Whether there are genuine benefits for mental health in older adults cross-culturally remains unknown. This study explored the consistency of this association across 16 different nations.

METHODS

For this epidemiological study, we used data from adults aged 65 years or older across 16 countries in the USA, Europe, and Asia, represented in five longitudinal studies (ELSA, JAGES, HRS, SHARE and CHARLS; N=93 263, 45-62% female, mean age 72-76 years, data collected 2008-20). We harmonised measures of self-reported engagement in hobbies and past-times, depressive symptoms (validated scales), and Likert scale responses for self-reported health, happiness, and life satisfaction. We conducted fixed-effects models and longitudinal regression models of hobbies and mental health for each country and then pooled in multinational meta-analyses. We accounted for all time-constant factors including those unobserved (eg, genetics, past leisure behaviour, medical history, psychological traits) and identified time-varying factors (eg, sociodemographic background, clinical conditions, daily functioning). We tested the potential moderating effects of country-level determinants of health in meta-regressions and multilevel models.

FINDINGS

Meta-analytic fixed-effects findings showed that having a hobby was associated with fewer depressive symptoms (pooled coefficient -0·10, 95% CI -0·13 to -0·07, I2=69·5%, H2=3·28), and higher levels of self-reported health (0·06, 0·03 to 0·08, I2=48·1%, H2=1·93), happiness (0·09, 0·06 to 0·13, I2=67·0%, H2=3·03), and life satisfaction (0·10, 0·08 to 0·12, I2=33·6%, H2=1·51). Results were consistent in meta-analyses of longitudinal regression models testing directionality of findings. Macro-level factors such as life expectancy, world happiness index, country wealth, and income inequality predicted prevalence of hobby engagement, but they showed only marginal moderating effects on the association between hobbies and mental health.

INTERPRETATION

Despite some heterogeneity in measurement between the cohorts, the apparent universality of the health benefits of hobbies internationally suggests that facilitating greater opportunities for engagement across demographic groups and between countries could be an important part of multidisciplinary care. Findings have implications for social prescribing schemes (currently in trial in many countries) and multidisciplinary work on origins and human behavioural patterns of hobby engagement.

FUNDING

National Endowment for the Arts, Wellcome Trust, Belgian Nnational Scientific Fund (FNRS).

Association between adverse childhood experiences and social integration among older people in Japan: Results from the JAGES study

Social integration, network, and support are beneficial to health. However, there is little evidence of the association between adverse childhood experiences (ACEs) and social integration in later life. This study investigates the association between ACE history and social integration in older people. We used data from the Japan Gerontological Evaluation Study (JAGES) 2013, which conducted a self-reported survey of functionally independent people aged ≥ 65 years from 30 municipalities across Japan and yielded information on ACE history. We conducted a Poisson regression analysis with robust error variances to assess the association between ACE history and social integration, adjusting for sex, age, childhood economic hardship, adult socioeconomic status, health status, living status, and trust in others. The number of respondents with at least one incident of ACE was approximately 36.8%. The prevalence ratios for those who reported a history of ACEs were as follows: housebound 1.495 (95% confidence interval [CI]: 1.19-1.88), small network size 1.146 (95% CI: 1.10-1.19), low network contact 1.059 (95% CI: 1.00-1.059), non-membership sports group 1.038 (95% CI: 1.00-1.07), and non-membership hobby group 1.06 (95% CI: 1.03-1.09). Among older people in Japan, a history of ACEs is inversely associated with social integration. These findings support the life course approach and suggest that adverse events in early life may have an impact on social life in old age. In order to promote healthy aging, it is important to recognize the significant impact of early-life adversities that can extend into later life.

Built Environments and Frailty in Older Adults: The JAGES Longitudinal Study Using Mediation Analysis

OBJECTIVES

The purpose of this study was to investigate the association between subjective built environment and the onset of frailty in older adults living in the community. In addition, we examined whether daily walking time, depressive symptoms, and social support from neighbors and friends are mediating factors.

DESIGN

This was a longitudinal study using prospective cohort data from the 2013 Japan Gerontological Evaluation Study.

SETTING AND PARTICIPANTS

Participants included 38,829 older adults who were not frail recruited from 22 cities and towns.

METHODS

The dependent variable, frailty, was assessed using the Kihon checklist. The explanatory variables were 5 items for the subjective built environment. The mediating variables were walking time of at least 30 minutes per day, a Geriatric Depression Scale (GDS) score of at least 5 points, and social support from neighbors and friends. We performed a causal mediation analysis of mediating effects between each built environment and frailty onset. Furthermore, the proportion of mediation was estimated.

RESULTS

After 3 years of follow-up, frailty emerged in 2232 adults (6.7%) in 2016. Access to parks and sidewalks, access to fresh food stores, houses or facilities where people feel free to drop in, and fascinating views, or buildings reduced the onset of frailty. Mediators significantly associated with the built environment and onset of frailty were access to parks and sidewalks (walking time: 5.9%, GDS: 22.9%, social support: 5.9%), access to fresh food stores (GDS: 31.9%, social support: 4.0%), hills and steps (GDS: 20.6%), houses or facilities where people feel free to drop in (walking time: 4.0%, GDS 28.0%, social support: 10.4%), and fascinating views, or buildings (walking time: 7.8%, GDS: 42.1%, social support: 12.0%).

CONCLUSIONS AND IMPLICATIONS

We found that walking time, depression, and social support were mediating factors in the relationship between built environment and the onset of frailty.

[Association between use of the "health-supportive" roadside station and self-rated health: A three-wave longitudinal study]

Objective　Mutsuzawa town, Chiba Prefecture, relocated a "health-supportive" roadside station in 2019. The underlying hypothesis is that older people who use the roadside station will have better self-rated health than those who do not use it. We aimed to verify whether roadside station use was associated with a decrease in poor self-rated health.Method　This was a longitudinal study that compared and evaluated the roadside station use and non-use groups using three-wave panel data before and after relocation of the roadside station in September 2019. To obtain three-wave panel data, self-administered questionnaires were mailed three times: in July 2018 (FY 2018) before the station was relocated and in November 2020 (FY 2020) and January 2022 (FY 2021) after the relocation in 2019. The dependent variable was poor self-rated health in FY 2021, and the independent variable was use of the roadside station as of FY 2020. Covariates included basic characteristics from FY 2018, as well as going out, social participation, and interacting on social networks in FY 2018 and FY 2020. A multivariate analysis was conducted using multiple imputation to complete missing values for the Crude model, which included the basic attributes of FY 2018 (Model 1); going out, social participation, and interacting on social networks in FY 2018 (Model 2); and going out, social participation, and interacting on social networks in FY 2020 (Model 3). The cumulative incidence rate ratio (CIRR), 95% confidence intervals, and P-values were calculated using a modified Poisson regression analysis for each model.Results　Of the 576 participants, 344 (59.8%) were roadside station users. The multivariate analysis adjusted for basic attributes revealed that the number of people with poor self-rated health in the user group was significantly lower than that in the non-user group, with a CIRR of 0.67 (95% confidence interval: 0.45-0.99, P=0.043). However, the adjusted model showed a CIRR of 0.71 (95% confidence interval: 0.48-1.06, P=0.096) for going out, social participation, and interacting on social networks in FY2020 after the roadside station opened.Conclusion　Findings of this study revealed that, after adjusting for confounding factors prior to relocation of the roadside station, the number of people with poor self-rated health decreased in the user group. Thus, such commercial facilities as roadside stations, which give users an opportunity to go out and meet people, can provide a "naturally healthy" environment.

Oral Self-Care, Pneumococcal Vaccination, and Pneumonia Among Japanese Older People, Assessed With Machine Learning

BACKGROUND

Pneumonia is a leading cause of death worldwide. It is a particularly serious burden in older people, as they tend to have a weakened immune response. Identifying the role of oral self-care and pneumococcal vaccination in healthy, independent older people can aid pneumonia prevention among them. This study investigated the associations between oral self-care, pneumococcal vaccination, and pneumonia experience among independent older people.

METHODS

This cross-sectional study used data from the 2016 Japan Gerontological Evaluation Study. We used machine learning to examine the association between oral self-care and the experience of pneumonia over the previous year, stratified by pneumococcal vaccination. The covariates were sex, age, years of education, equivalent annual income, medical history of stroke, oral health status (choking, dryness, number of teeth), and smoking status. The analysis included 17 217 independent older people aged 65 and over.

RESULTS

The prevalence of pneumonia experienced among those who brushed their teeth once or less per day was 4.5% and 5.3% for those with and those without pneumococcal vaccinations, respectively. In the unvaccinated group, the odds ratio of pneumonia experience for those who brushed their teeth once or less a day was 1.57 (95% confidence interval: 1.15-2.14) compared to those who brushed their teeth 3 or more times a day. By contrast, there was no significant association between the frequency of toothbrushing and the experience of pneumonia among people who received pneumococcal vaccination.

CONCLUSIONS

Oral care influenced the experience of pneumonia among independent older people who did not receive pneumococcal vaccination.

Reduced number of teeth with and without dental prostheses and low frequency of laughter in older adults: Mediation by poor oral function

PURPOSE

Laughter is expected to have health-protective effects, but the potential link between tooth loss and laughter remains unclear. Therefore, this study aimed to examine the association between tooth loss and a low frequency of laughter among older adults in Japan, to elucidate whether this association could be mitigated by dental prostheses, and to evaluate the magnitude of the association mediated by poor oral function.

METHODS

We used cross-sectional data from 157,708 functionally independent participants aged ≥65 years (46.3% male) from the Japan Gerontological Evaluation Study. A modified Poisson regression model was applied to examine the association between the number of remaining teeth (≥20/10-19/0-9), dental prostheses use, and infrequent laughter (i.e., laughing never or almost never). Causal mediation analysis was performed to assess whether the association was mediated by difficulties in eating hard foods, choking, or dry mouth.

RESULTS

Among the participants, 9,129 reported infrequent laughter. Participants with ≤9 and 10-19 teeth who did not use dental prostheses had a 1.29 and 1.14 times higher likelihood of infrequent laughter than those with ≥20 teeth, respectively. Furthermore, difficulty eating hard foods, choking, and dry mouth mediated 22.8%, 0.4%, and 4.3% of the association between fewer remaining teeth and infrequent laughter, respectively. Meanwhile, we did not find evidence for the differences in infrequent laughter between participants with ≤19 teeth using dental prostheses and those with ≥20 teeth.

CONCLUSIONS

Tooth loss among individuals without dental prostheses was associated with infrequent laughter, and this association was mediated by poor oral function.

Association between adverse childhood experiences and marital status among Japanese older adults

BACKGROUND

Marital status is a well-known social determinant of health. Adverse childhood experiences (ACEs) affect attachment, critical to establishing and maintaining intimate relationships, such as marital status.

OBJECTIVE

This study examined the association between ACEs and marital status among older Japanese adults.

PARTICIPANTS AND SETTING

This research used data from a nationwide population-based study among functionally independent people aged 65 and above in Japan.

METHODS

ACEs were assessed by self-reported questionnaires on the following experiences before 18 years old: parental death, parental divorce, parental mental disease, exposure to intimate partner violence, physical abuse, psychological neglect, psychological abuse, and poverty. Marital status was asked as currently having a spouse (including common-law marriage), widowed, divorced, or unmarried. Associations between the total number of ACEs and marital status were analyzed by multinomial logistic regression.

RESULTS

Three or more ACEs showed higher risks of being widowed, divorced, or unmarried. Psychological neglect led to higher divorce risks among males (RRR, 95%CI = 1.41, 1.13-1.76) and females (RRR, 95%CI = 1.56, 1.28-1.89). Childhood poverty showed higher risks of unmarried among males (RRR, 95%CI = 1.25, 1.02-1.53) and females (RRR, 95%CI = 1.41, 1.18-1.69). Association between ACEs and divorce risks showed gender differences (RRR, 95%CI of having three or more ACEs in males: 2.19, 1.66-2.90; in females: 3.45, 2.71-4.38; p for interaction = 0.034).

CONCLUSIONS

ACEs showed higher risks of being widowed, divorced, and unmarried among older Japanese people. Policy to tackle ACEs and research investigating how ACEs, attachment, and relationship quality influence marital status are required to promote well-being in later life.

Co-Payments and Inequality in Gingival Bleeding and Dental Visits

OBJECTIVES

Japan's universal health insurance covers a wide range of dental treatments, and the co-payment rates differ by age. We investigated whether the inequality in gingival bleeding and dental visits was smaller amongst those with lower co-payment rates.

METHODS

This cross-sectional study used data from the 2019 Japan Gerontological Evaluation Study. The participants were functionally independent adults aged 65 years or older. The dependent variables were current gingival bleeding as a symptom of periodontal diseases and dental nonattendance for treatment in the past year. The independent variables were ridit scores of equivalent income and educational status. For covariates, we used age, sex, and the number of remaining teeth. To evaluate the inequalities, we used the slope index of inequality (SII) and the relative index of inequality (RII). We also conducted stratified analyses by co-payment rates (30%, 20%, and 10%) to clarify the difference in inequalities by co-payment rate.

RESULTS

A total of 15,389 participants were included in the analysis; their mean age was 71.8 (SD = 4.1) and 51.8% were women. There were significant absolute and relative inequalities in gingival bleeding and dental visits by equivalent income and education. With regards to educational status, inequalities were lower with a decrease in the co-payment rate. In particular, relative inequality by education in gingival bleeding was the largest amongst the 30% co-payment group (RII, 1.918; 95% confidence interval [CI], 1.386 to 2.656). For gingival bleeding, the absolute and relative inequality by equivalent income were not significant amongst the 10% co-payment group (SII, -0.003; 95% CI, -0.003 to 0.028; RII, 1.006; 95% CI = 0.676 to 1.498).

CONCLUSIONS

A low co-payment rate was associated with smaller inequalities in gingival bleeding and dental visits by equivalent income and educational status.

[Association between social participation and frailty among older adults: A longitudinal study from Japan Gerontological Evaluation Study]

Objective　In Japan, measures to prevent frailty among older adults have been implemented. Promotion of social participation is a key measure, but few longitudinal studies have examined the relationship between the types and number of social participation and frailty onset. In this study, we aimed to clarify the relationship between the types and number of social participation and frailty onset using longitudinal data from a large sample of older adults in municipalities in Japan.Methods　We used the 2016 and 2019 panel survey data from the Japan Gerontological Evaluation Study (JAGES). The analysis included 59,545 individuals from 28 municipalities who responded to the JAGES survey in both 2016 (at baseline) and 2019 (at follow-up). We excluded individuals who were dependent on activities of daily living at baseline and non-responders, and those who were frail or with no information about frailty. The dependent variable was frailty onset (≥8 out of 25 points on the basic checklist) at follow-up, and the independent variables were the types and number of types of social participation at baseline. We included 11 variables as potential confounders. We used multiple imputations to complete the missing values and used modified Poisson regression to examine the association between social participation and risk of frailty onset.Results　Of the 59,545 participants, 6,431 (10.8%) were frail onset at follow-up. After multiple imputations (minimum 64,212, maximum 64,287), the risk of frailty onset at follow-up was lower for eight types of social participation, excluding senior citizens' clubs, (nursing care [risk ratio; 0.91], paid work [0.90], volunteer groups [0.87], neighborhood associations [0.87], learning or cultural groups [0.87], activities intended to teach skills or pass experiences to others [0.85], hobby groups [0.81], and sports groups or clubs [0.80]; P<0.05), than no social participation. Additionally, individuals who participated in more types of social participation were at a lower risk of frailty than those with no social participation (P for trend <0.001).Conclusions　The risk of frailty onset was lower among individuals who participated in eight types of social participation at baseline and among those who participated in more types of social participation than those with no social participation. The results suggest that social participation is a useful measure to prevent frailty for extending healthy life expectancy.

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.

Association between diversity levels of member composition in group activities of older adults and the occurrence of need for care: the JAGES 2013-2019 longitudinal study

BACKGROUND

Participating in groups with diverse members is associated with improved health among older adults. The study examined the relationship between diversity of group members and needed support or long-term care.

METHODS

We conducted a longitudinal study for the Japan Gerontological Evaluation Study with 61,281 participants aged ≥ 65 years who were surveyed in 2013 and followed-up for six years. We assessed three dimensions of the diversity of the participating members (sex, age, and region of residence). We then graded the diversity level into four categories: level 0 (not in any group), level 1 (in a group without diversity or in a group with diversity in one of the three factors), level 2 (in a group with diversity in two of the three factors), or level 3 (in a group with diversity across all factors). We adjusted for 12 covariates using Cox hazard survival analysis models with hazard ratios (HRs) and 95% confidence intervals (CIs) estimated for the association between group members' diversity levels and needed support or long-term care. The same study was conducted when stratified by employment status at baseline.

RESULTS

Participants in social participation groups with more diverse group members had a lower incidence of needed support or long-term care as compared to their counterparts. Compared to those with no participation group, HR decreased by 14% to 24% with increasing levels of diversity. The HR for the level of care needed for participants in the social participation group with high residential diversity was 0.89 (95% CI: 0.84-0.94). For participants who were currently unemployed, HR reductions ranged from 16%-28% with increasing levels of diversity compared to the non-participating group. No association was found for employed participants.

CONCLUSIONS

The reason the HRs of Japanese elderly people certified as needing support or care are lower when the diversity of participating groups is higher could be owing to the presence of a variety of people and the diversification of social networks, which facilitates the building of bridging social relational capital. Public health policies that encourage participation in diverse organizations will be important in the future.

Association of social isolation and loneliness with chronic low back pain among older adults: A cross-sectional study from Japan Gerontological Evaluation Study (JAGES)

BACKGROUND

Per the biopsychosocial model, pain, especially chronic low back pain, which often presents with nonspecific pain, requires a comprehensive approach involving social factors. However, the association of social factors, including social isolation and loneliness, with this condition remains unclear. This study examined the cross-sectional association of social isolation and loneliness with chronic low back pain among older adults.

METHODS

We recruited functionally independent older adults through a mail survey in 2019 from the Japan Gerontological Evaluation Study (JAGES). Chronic low back pain was defined as low back pain lasting more than three months. Social isolation was identified based on face-to-face and non-face-to-face interactions ("not isolated," "isolated tendency," and "isolated"). Loneliness was assessed using the UCLA Loneliness Scale ("not lonely," "lonely tendency," and "lonely").

RESULTS

Consequently, 21,463 participants were analyzed (mean age: 74.4 years; 51.5% females); 12.6% reported chronic low back pain. Multivariable Poisson regression analysis revealed that loneliness was significantly associated with the likelihood of chronic low back pain; compared with "not lonely", the prevalence ratio (PR) was 1.14 (95% confidence interval [CI]: 1.05-1.25) for "lonely tendency" and 1.40 (1.27-1.54) for "lonely." Social isolation was not associated; compared with "not isolated," the PR (95% CI) was 0.96 (0.88-1.05) for "isolated tendency" and 0.99 (0.89-1.10) for "isolated." A positive multiplicative interaction between social isolation and loneliness for chronic low back pain was found.

CONCLUSIONS

Lonelier individuals were more likely to experience chronic low back pain, and those with loneliness and social isolation were synergistically more likely for this condition.

Frequency of social participation by types and functional decline: A six-year longitudinal study

Social participation is effective for preventing functional decline in older people. However, researchers have not fully explored how different frequencies of social participation by type. We aimed to clarify the relationship between the frequency of social participation by type and functional decline. We used data from the Japan Gerontological Evaluation Study, which consists of individuals aged 65 years and older who were not eligible to receive public long-term-care insurance benefits. From 13 municipalities, 51,968 respondents who met the criteria were included in the analysis. We used a sex-stratified Cox proportional hazards model. The outcome was the new incidence of functional decline during a six-year follow-up, and the exposure was the frequency of social participation of one of the following six types: sports, hobbies, volunteering, neighborhood, senior clubs, and industry groups. The frequency was categorized as "never," "a few times a year," "once or twice a month," and "once a week or more." We set non-participation in each activity as the reference, and we adjusted for 12 potential confounders (i.e., sociodemographic and health-related factors). After we adjusted for confounders, participation in sports and hobbies once or twice a month, once a week or more was protectively associated with functional decline. We found a similar association for participation in neighborhood a few times a year. Our findings demonstrate the importance of considering the effects of different types and frequencies of activities when promoting social participation among older people as part of public health policies.

Cooking skills modify the association between oral health and mortality

Poor oral health has been linked to an increased risk of mortality. People with good cooking skills may be able to cope with problems caused by oral dysfunction, such as restricted food choice. This study investigated whether cooking skills modified the association between oral health status and mortality. A 3-year follow-up was conducted among participants of the Japan Gerontological Evaluation Study, a population-based cohort study of Japanese adults aged 65-101 years. Oral health assessment comprised number of teeth and three oral functions (awareness of swallowing difficulty, decline in masticatory function, and dry mouth). Cooking skills were assessed using a valid scale adapted for Japanese participants. Mortality from 2016 to 2019 was analysed for 10,121 respondents. Cox regression models were used to estimate hazard ratios for mortality risk adjusting for potential confounders, including sociodemographic factors and health status. During the follow-up, there were 488 deaths (4.8% of all participants). Both fewer teeth and poor oral function were associated with a greater mortality risk. Cooking skills modified the association only for oral function. Stratification by cooking skill score showed that the hazard ratios for ≥2 oral difficulties (vs. none) was 2.06 (95% confidence interval: 1.43-2.96) among those with low cooking skills and 1.25 (95% confidence interval: 0.92-1.71) among those with high cooking skills after adjusting for potential confounders. Improving cooking skills may be key to mitigating health risks owing to poor oral functions.

Hobby engagement and mental wellbeing among people aged 65 years and older in 16 countries

Growing aging populations pose a threat to global health because of the social and psychological challenges they experience. To mitigate this, many countries promote hobby engagement to support and improve mental health. Yet, it remains unclear whether there is consistency in benefits across different national settings. We harmonized measures of hobby engagement and multiple aspects of mental wellbeing across 16 nations represented in five longitudinal studies (N = 93,263). Prevalence of hobby engagement varied substantially across countries, from 51.0% of Spanish respondents to 96.0% of Danish respondents. Fixed effects models and multinational meta-analyses were applied to compare the longitudinal associations between hobbies and mental wellbeing. Independent of confounders, having a hobby was associated with fewer depressive symptoms (pooled coefficient = -0.10; 95% confidence intervals (CI) = -0.13, -0.07), and higher levels of self-reported health (pooled coefficient = 0.06; 95% CI = 0.03, 0.08), happiness (pooled coefficient = 0.09; 95% CI = 0.06, 0.13) and life satisfaction (pooled coefficient = 0.10; 95% CI = 0.08, 0.12). Further analyses suggested a temporal relationship. The strength of these associations, and prevalence of hobby engagement, were correlated with macrolevel factors such as life expectancy and national happiness levels but overall, little variance in findings was explained by country-level factors (<9%). Given the relative universality of findings, ensuring equality in hobby engagement within and between countries should be a priority for promoting healthy aging.