Comparing Potential Contributors of Health-Related Quality of Life and Mortality Among US Older Adults

Background Many contributing factors can influence individuals’ health, and these factors may not affect health outcomes equally. This study compared the importance of 38 predictors of health-related quality of life (HRQOL) and 2-y mortality for US older adults. Methods Data were from the Medicare Health Outcome Survey Cohort 23 (baseline 2020, follow-up 2022). This study included participants ≥65 y ( N = 142,551). HRQOL measures included physically unhealthy days (PUD), mentally unhealthy days (MUD), and activity limitation days (ALD) from the Healthy Days questions and 3 measures from the Veterans RAND 12-Item Health Survey (VR-12). A variable’s importance was measured as the average gain in R 2 after adding the variable in all submodels. Results For physical health (PUD), pain interfered with daily activities was the most important predictor with an importance score (I) of 8.4, indicating that this variable contributed 8.4% variance of PUD. Other leading predictors included pain interfered with socializing (I = 7.3) and pain rating (I = 6.7). For mental health (MUD), depression (I = 11.6) was far more important than any of the other predictors, contributing 38% of the total importance. For perceived disability (ALD), pain interfered with socializing was the most important predictor (I = 8.3), followed by difficulty doing errands (I = 6.1) and pain interfered with activities (I = 6.0). Of note, this general pattern was consistent for VR-12 HRQOL measures. Variables’ importance scores for 2-y morality were very different from that for HRQOL. Age (I = 2.8) and difficulty doing errands (I = 2.6) were the most important variables. Conclusions This study demonstrated a large discrepancy in the variables’ importance for HRQOL and 2-y mortality. Functional limitations/disabilities and geriatric syndromes were more important for the prediction of HRQOL than were chronic conditions and other factors combined. Highlights For older adults, large differences were found in variable importance for explaining health-related quality of life (HRQOL) and 2-y mortality among 38 explanatory variables, including functional limitations, geriatric syndromes, chronic conditions, and other factors. Pain and pain interference, difficulty doing errands, difficulty concentrating, memory problems, problems with walking/balance, and depression were the most important predictors of HRQOL. Age, marital status, education, difficulty doing errands, congestive heart failure, chronic obstructive pulmonary disease, and any cancer were more important for 2-y mortality than HRQOL. Health care providers and policy makers should focus on the impact of multimorbidity and the interaction between often multifactorial conditions, as opposed to focusing only on individual diseases.