Multimorbidity and functional status in older people: a cluster analysis.

PURPOSE: Multimorbidity and frailty are complex conditions often present in older people. The aim of this study was to identify clusters of chronic diseases in robust and frail individuals and compare sociodemographic and health characteristics between these clusters. METHODS: This cross-sectional study used information from electronic health records and a baseline assessment, which included the Timed Up and Go test of physical performance as a measure of frailty. Multiple correspondence and cluster analyses were performed to identify groups. RESULTS: A total of 813 individuals (55.1% women; mean age 77.4 years, SD = 5.0) were studied. Frail individuals (n = 244) were older and had a poorer health status than robust individuals (n = 569). Three clusters were identified among the robust (RC1, n = 348; RC2, n = 139 and RC3, n = 82) and four among the frail individuals (FC1, n = 164; FC2, n = 23; FC3, n = 44 and FC4, n = 13). The RC1 and FC1 had a better health status (specifically, less polypharmacy, lower chronic disease burden and better self-perceived health) than RC2-RC3 and FC2-FC3-FC4, respectively. Diseases associated with mobility limitation and limb pain were more common in RC2 and FC2 than in the other clusters. Cardiovascular diseases and risk factors were more prevalent in RC3 and FC3. Among the frail a new cluster emerged, FC4, containing individuals with higher rates of cognitive and eye problems and a clearly poor health status. CONCLUSION: This exploratory study may provide relevant information for the clinical management of older patients with multimorbidity, even though the chronic disease clusters identified were similar in robust and frail individuals.