Association of the combination of social isolation and living alone with cognitive impairment in community-dwelling older adults: The IRIDE Cohort Study

Background: Living alone has been associated with cognitive impairment; however, findings have been inconsistent. Social isolation among older adults who live alone may contribute to cognitive impairment. This study was carried out to examine the association of social isolation and living alone with cognitive impairment in community-dwelling older adults. Methods: In this cross-sectional study, data from the Integrated Research Initiative for Living Well with Dementia Cohort Study, which comprises pooled data from five community-based geriatric cohorts, was used. Social isolation was defined as infrequent interactions with others. Participants were categorized into four groups based on their social isolation and living alone statuses. Cognitive function was assessed using the Mini-Mental State Examination, with a score <24 indicating cognitive impairment. The association between social isolation combined with living alone and cognitive impairment was analyzed using logistic regression. Results: Of the 4362 participants included in the analysis (mean age 75.6 years, 44.3 % male), 11 % had cognitive impairment. Regardless of living alone, social isolation was associated with cognitive impairment (no social isolation x not living alone: reference, social isolation x not living alone; odds ratio (OR): 1.74, 95 % confidence interval (CI): 1.29 -2.33, social isolation x living alone; OR: 2.10, 95 % CI: 1.46 -3.01). Conclusions: Social isolation is associated with cognitive impairment; however, living alone is not intrinsically associated with cognitive impairment in older adults. Healthcare providers must focus on social interactions to prevent cognitive impairment in older adults rather than simply focusing on living arrangements.