OBJECTIVE: To determine if multimorbidity is associated with functional status, and to assess if multimorbidity predicts declining functional status over a 5-year time frame, after accounting for baseline functional status and other potential confounding factors. DESIGN: Analysis of an existing population-based cohort study. SETTING: Manitoba. PARTICIPANTS: Community-dwelling adults aged 65 and older. MAIN OUTCOME MEASURES: Age, sex, education, and the Mini-Mental State Examination (MMSE) and Center for Epidemiological Studies Depression Scale (CES-D) scores were recorded for each patient. Multimorbidity was measured using a simple tally of self-reported diseases. Function was measured using the Older Americans Resources and Services scale in 1991 to 1992 and again 5 years later. Good or excellent level of function was compared with level of disability (mild or moderate or higher). Cross-sectional and prospective analyses were conducted. RESULTS: In a cross-sectional analysis, multimorbidity predicted disability. The unadjusted odds ratio (OR) (95% CI) for disability was 1.45 (1.39 to 1.52) for each additional chronic illness. In models adjusting for age, sex, education, and MMSE and CES-D scores, the adjusted OR (95% CI) was 1.35 (1.29 to 1.42) for each additional chronic illness. Multimorbidity also predicted disability 5 years later. The unadjusted OR (95% CI) was 1.31 (1.24 to 1.38). In models adjusting for age, sex, education, and MMSE and CES-D scores in addition to baseline functional status, the adjusted OR (95% CI) was 1.15 (1.09 to 1.24). CONCLUSION: Multimorbidity predicts disability in cross-sectional and prospective analyses.
