Do older adults with multimorbidity prefer institutional care than those without multimorbidity? The role of functional limitation

BACKGROUND: Population ageing and social transformation present tremendous challenges to the informal support system of older adults, which engendered institutional care in China. This study aimed to examine the association between multimorbidity and institutional care willingness, and investigate whether there is an interaction effects between multimorbidity and functional limitations on institutional care willingness among Chinese older adults. METHODS: Data were obtained from the sixth National Health Service Survey of Shandong province, China. The sample included 8583 older adults (age ≥ 60 years; 51.7% women), 44.8% without chronic diseases, 34.8% and 20.4% with one chronic condition and multimorbidity, respectively. Multivariable logistic regression models and marginal effects analysis were used to the interaction effects analysis. RESULTS: A total of 666 (7.8%) participants had institutional care willingness in Shandong, China. Participants with multimorbidity were more likely to have institutional care willingness than their peers without chronic condition (OR = 1.25, 95% CI = 1.06, 1.55) after adjusted for confounders. Marginal effect analysis showed that under the condition that other variables remain unchanged, the probability of them with multimorbidity choosing institutional care for older adults with functional limitations was 6.9% lower than those without multimorbidity (95% CI = -0.128, -0.010, P = 0.023). The interaction effect between chronic health conditions and functional limitation for older adults to choose institutional care was statistically significant, and the average interaction effect was 4.83% (Z = -2.70, [Formula: see text] = 0.0189, P < 0.05). CONCLUSIONS: This relationship between multimorbidity and institutional care willingness varied by functional limitations. To better meet the care needs among older adults with multimorbidity and functional limitations, more resources and incentives should be provided to encourage the building-up of eldercare institutions. The governments should also establish long-term care system and to provide better home-based care for older adults, as older adults who prefer home care remain the majority. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-02812-2.