Living Alone, Cognitive Function, and Well-Being of Japanese Older Men and Women: A Cross-Sectional Study

This study examined the interaction of living alone and cognitive decline in relation to the well-being of older men and women. We analyzed the data from a cross-sectional, self-administered questionnaire survey of community-dwelling older adults in Tokyo, who were aged 65+ and not on long-term care. The questionnaire included the 10-item self-administered dementia checklist (SDC), the WHO-5 Well-Being Scale, a question on their living arrangement, and participants' baseline characteristics and social support and social contact. The analyses were stratified by sex and fitted with linear regression models with interaction. A total of 34,255 men and 41,056 women participated. Sample mean age was 73.5 (SD 6.1) for men and 73.6 (SD 6.0) for women, and 18.5% and 26.0% lived alone. The distribution of SDC scores indicated 95.9% and 97.0% had a cognitive status varying from intact to possible mild dementia. Cognitive decline showed a linear association with lower well-being in men (beta -0.53; 95% CI -0.58, -0.48; p < 0.001) and women (beta -0.38; 95% CI -0.42, -0.34; p < 0.001). Compared to men and women living with others, those living alone experienced lower well-being as their cognitive function declined, and the interactions (living arrangements*SDC) were statistically significant. After controlling participants' characteristics and social support and social contact, the interaction was significant in men (p < 0.001) but not in women (p=0.46). Our findings support that older men and women living alone experience a slightly steeper downward trajectory of cognitive decline and poor well-being than their counterparts living with others. The unequivocal effects of controlling confounding factors between men and women indicate the need for gendered countermeasures by welfare services.