Functional ability of community-dwelling older adults in Switzerland and its associations with multimorbidity and socioeconomic determinants: a longitudinal analysis of the Swiss Survey of Health, Ageing and Retirement in Europe (SHARE)

Functional ability is central to healthy ageing, yet population-level evidence on functional ability in Switzerland remains limited as population ageing increases the demand for long-term care and rehabilitation services. Using longitudinal data from the Swiss Survey of Health, Ageing and Retirement in Europe (SHARE) and a validated functional ability score (0–100), we examined functional ability among community-dwelling adults aged 50 years and older. We investigated its association with multimorbidity, operationalized as both a binary disease count (defined as the presence of two or more chronic conditions) and a weighted disease burden score (0–10), over time using mixed-effects models. Two models were fitted accordingly and adjusted for age, sex, education, financial hardship, employment status, language, citizenship, living situation, and birth cohort. Our results showed that multimorbidity was consistently associated with lower functional ability across both operationalizations, with effects becoming more pronounced at older ages and among individuals experiencing financial hardship or with a lower level of education. This study provides a population-based, longitudinal description of functional ability among older adults in Switzerland, demonstrating that multimorbidity is negatively associated with functional ability in an age-dependent and socially patterned manner. These findings support functional ability as a policy-relevant indicator for monitoring healthy ageing and have direct implications for long-term care planning, rehabilitation, and equity-sensitive approaches to healthy ageing.