Sex-specific multimorbidity clusters and all-cause mortality among community-dwelling older adults: findings from the ASPREE cohort

Abstract

Abstract Background Multimorbidity is common in older adults, but sex differences in chronic condition clustering remain unclear. This study explored multimorbidity clusters and their associations with all-cause mortality among community-dwelling adults aged 70 years and over. Methods This was a secondary analysis of data from 16 095 Australian ASPREE participants aged ≥70 years without prior dementia or cardiovascular disease. Fifteen baseline chronic conditions were grouped using latent class analysis (LCA). Observed-to-expected (O/E) ratios characterized conditions over-represented within clusters, and Cox proportional hazards models assessed associations with all-cause mortality. Results Among 16 095 participants (mean age 75.3 years), 88.3% had multimorbidity at baseline; 4217 deaths occurred over a median follow-up of 10.85 years. Five clusters were identified overall: hypertension and dyslipidemia (52.1%), gout and metabolic (14.4%), depressive symptoms, osteoporosis, and frailty (10.0%), anemia and kidney disease (10.2%), and hypotension, thyroid disorder, and past cancer (13.3%). Sex-stratified analyses revealed 3 clusters in males and 4 in females. The frailty, depressive symptoms and osteoporosis cluster was associated with higher mortality in both sexes (adjusted hazard ratio [aHR] 1.56 [95% confidence interval (CI) 1.40-1.73] in males; 1.68 [1.49-1.89] in females). Higher mortality was also observed for the metabolic, gout and kidney disease cluster in males (aHR 1.63 [1.47-1.81]) and the gout, anemia and kidney disease cluster in females (aHR 1.96 [1.74-2.21]). Conclusions Distinct multimorbidity clusters were identified overall and in sex-stratified analyses. These hypothesis-generating findings suggest the potential clinical utility of multimorbidity clusters to identify individuals at increased risk of death, but further research is needed.