Factors associated with worsening health-related quality of life among a Medicare Advantage population

Introduction

Health related quality of life (HRQOL) is an important predictor of health outcomes and healthcare costs. This study explored predictors of worsening HRQOL using the Healthy Days instrument, which is included in the Health Outcomes Survey (HOS). The HOS is administered to a random sample of Medicare Advantage enrollees each year and repeated two years later. Healthy Days measures recent physically and mentally unhealthy days (PUHD and MUHD).

Population and Study Design

Study participants were members of the 2011 HOS cohort in a large Medicare Advantage plan who reported 0-13 PUHD or MUHD. Decision Tree Analysis identified the most important predictors of an increase between 2011 and 2013 to ≥14 PUHD or MUHD.  Variables for demographics, functional/health status, utilization, and clinical conditions were assigned a relative Variable Importance (VI) value.

Results

The final models applied to 5,100 survey respondents with PUHD data (11.3% reported an increase) and 5,526 with MUHD data (6.9% reported an increase). The most important predictor was less than good baseline general health status (VI=1). Difficulties walking at baseline (VI=0.63), diagnosis of musculoskeletal back or neck pain (VI=0.5), low income (VI=0.23), and cardiovascular disease (VI=0.18) were important predictors of increased PUHD. Depression (VI=0.73) disability (VI=0.45), difficulties bathing (VI=0.22) or walking (VI=0.18) at baseline, and age ≥83 years (VI=0.21) at baseline were important predictors of increased MUHD.  

Conclusions

People with less than good baseline general health, functional limitations, chronic conditions, low income, or advanced age may be at risk of worsening HRQOL.