Background The efficacy of promoting social interactions to improve the health of older adults is not fully established due to residual confounding and selection bias. Methods The government of Taketoyo town, Aichi Prefecture, Japan, developed a resident-centred community intervention programme called ‘community salons’, providing opportunities for social interactions among local older residents. To evaluate the impact of the programme, we conducted questionnaire surveys for all older residents of Taketoyo. We carried out a baseline survey in July 2006 (prior to the introduction of the programme) and assessed the onset of functional disability during March 2012. We analysed the data of 2421 older people. In addition to the standard Cox proportional hazard regression, we conducted Cox regression with propensity score matching (PSM) and an instrumental variable (IV) analysis, using the number of community salons within a radius of 350 m from the participant's home as an instrument. Results In the 5 years after the first salon was launched, the salon participants showed a 6.3% lower incidence of functional disability compared with non-participants. Even adjusting for sex, age, equivalent income, educational attainment, higher level activities of daily living and depression, the Cox adjusted HR for becoming disabled was 0.49 (95% CI 0.33 to 0.72). Similar results were observed using PSM (HR 0.52, 95% CI 0.33 to 0.83) and IV-Cox analysis (HR 0.50, 95% CI 0.34 to 0.74). Conclusions A community health promotion programme focused on increasing social interactions among older adults may be effective in preventing the onset of disability.

Background: We examined the associations of informal (eg, family members and friends) and formal (eg, physician and visiting nurses) social support with caregiver’s burden in long-term care and the relationship between the number of available sources of social support and caregiver burden. Methods: We conducted a mail-in survey in 2003 and used data of 2998 main caregivers of frail older adults in Aichi, Japan. We used a validated scale to assess caregiver burden. Results: Multiple linear regression demonstrated that, after controlling for caregivers’ sociodemographic and other characteristics, informal social support was significantly associated with lower caregiver burden (β = −1.59, P < 0.0001), while formal support was not (β = −0.30, P = 0.39). Evaluating the associations by specific sources of social support, informal social supports from the caregiver’s family living together (β = −0.71, P < 0.0001) and from relatives (β = −0.61, P = 0.001) were associated with lower caregiver burden, whereas formal social support was associated with lower caregiver burden only if it was from family physicians (β = −0.56, P = 0.001). Compared to caregivers without informal support, those who had one support (β = −1.62, P < 0.0001) and two or more supports (β = −1.55, P < 0.0001) had significantly lower burden. This association was not observed for formal support. Conclusions: Social support from intimate social relationships may positively affect caregivers’ psychological wellbeing independent of the receipt of formal social support, resulting in less burden.

We examined whether eating alone is associated with dietary behaviors and body weight status, and assessed the modifying effects of cohabitation status in older Japanese people. Data from the 2010 Japan Gerontological Evaluation Study, with a self-reported questionnaire for 38,690 men and 43,674 women aged ≥65 years, were used. Eating status was classified as eating with others, sometimes eating alone, or exclusively eating alone. We calculated adjusted prevalence ratios (APRs) of unhealthy dietary behaviors, obesity, and underweight, adjusting for age, education, income, disease, and dental status using Poisson regression. Overall, 16% of men and 28% of women sometimes or exclusively ate alone. Among those who exclusively ate alone, 56% of men and 68% of women lived alone. Men who exclusively ate alone were 3.74 times more likely to skip meals than men who ate with others. Among men who exclusively ate alone, those who lived alone had a higher APR than men who lived with others. Compared with subjects who ate and lived with others, the APRs of being obese (BMI ≥ 30.0 kg/m(2)) among men who exclusively ate alone were 1.34 (1.01-1.78) in those who lived alone and 1.17 (0.84-1.64) in those who lived with others. These combined effects of eating and living alone were weaker in women, with a potential increase in the APRs among those who ate alone despite living with others. Men who exclusively ate alone were more likely to be underweight (BMI < 18.5 kg/m(2)) than men who ate with others in both cohabitation statuses. Eating alone and living alone may be jointly associated with higher prevalence of obesity, underweight and unhealthy eating behaviors in men.

Empirical evidence investigating heterogeneous impact of retirement on mental health depending on social backgrounds is lacking, especially among older adults. We examined the impact of changes in working status on changes in mental health using Japanese community-dwelling adults aged ≥65 years participating in the Japan Gerontological Evaluation Study between 2010 and 2013 (N = 62,438). Between-waves changes in working status (“Kept working”, “Retired”, “Started work”, or “Continuously retired”) were used to predict changes in depressive symptoms measured by the Geriatric Depression Scale. First-difference regression models were stratified by gender, controlling for changes in time-varying confounding actors including equivalised household income, marital status, instrumental activities of daily living, incidence of serious illnesses and family caregiving. We then examined the interactions between changes in working status and occupational class, changes in marital status, and post-retirement social participation. Participants who transitioned to retirement reported significantly increased depressive symptoms (β = 0.33, 95% CI: 0.21–0.45 for men, and β = 0.29, 95% CI: 0.13–0.45 for women) compared to those who kept working. Men who were continuously retired reported increased depressive symptoms (β = 0.13, 95% CI: 0.05–0.20), whereas males who started work reported decreased depressive symptoms (β = −0.20, 95% CI: -0.38–-0.02). Men from lower occupational class (compared to men from higher class) reported more increase in depressive symptoms when continuously retired (β = −0.16, 95% CI: -0.25–-0.08). Those reporting recreational social participation after retirement appeared to be less influenced by transition to retirement. Retirement may increase depressive symptoms among Japanese older adults, particularly men from lower occupational class backgrounds. Encouraging recreational social participation may mitigate the adverse effects of retirement on mental health of Japanese older men.