Sex-specific multimorbidity clusters and all-cause mortality among community-dwelling older adults: findings from the ASPREE cohort
Rong Du, Swarna Vishwanath, Zimu Wu, Aung Zaw Zaw Phyo, Suzanne G Orchard, Kerry Sheets, Michael E Ernst, Joanne RyanAbstract
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; 4,217 deaths occurred over a median follow-up of 10.85 years. Five clusters were identified overall: hypertension & dyslipidemia (52.1%), gout & metabolic (14.4%), depressive symptoms, osteoporosis & frailty (10.0%), anemia & kidney disease (10.2%), and hypotension, thyroid disorder & past cancer (13.3%). Sex-stratified analyses revealed three clusters in males and four in females. The frailty, depressive symptoms & osteoporosis cluster was associated with higher mortality in both sexes (aHR 1.56 [95% CI 1.40–1.73] in males; 1.68 [1.49–1.89] in females). Higher mortality was also observed for the metabolic, gout & kidney disease cluster in males (aHR 1.63 [1.47–1.81]) and the gout, anemia & 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.