Social Isolation and Hospitalization in Community-Dwelling Older Adults by Dementia Status.

Background: Social isolation is a well-known risk factor for poor health outcomes, including incident dementia, yet its associations with outcomes among persons living with dementia are understudied. We examined the association between social isolation and hospitalization among a nationally representative sample of older adults with and without dementia.

Methods: This observational cohort study included 5 533 community-dwelling Medicare beneficiaries from the 2015 and 2016 National Health and Aging Trends Study (NHATS). Using multivariable logistic regression analyses, we examined associations between social isolation and hospitalization in the following year, examining differences by dementia status. Social isolation was measured using a 4-item typology. Dementia was identified using a prespecified classification in NHATS.

Results: 20.7% of older adults were socially isolated. Social isolation was more prevalent among persons with dementia (35.4%) than among those without dementia (19.0%) (p < .001). Among persons with dementia, social isolation was associated with 1.68 greater odds of hospitalization (confidence interval [CI]: 1.23-2.28), translating into a 9% average increase in the predicted probability of hospitalization for persons with dementia who were socially isolated compared to those who were not (p = .001). In the combined sample that included persons with and without dementia, there was a significant moderation effect of dementia on the association between social isolation and hospitalization (odds ratio: 1.70; CI: 1.19-2.43).

Conclusions: For persons with dementia, social isolation is prevalent and associated with greater odds of subsequent hospitalization. Efforts to reduce acute healthcare utilization should explore ways to bolster social connection to improve health outcomes among persons with dementia.