OBJECTIVES: Older adults with prostate cancer (PC) are at risk of polypharmacy, which further complicates disease management and health-related quality of life (HRQoL). This study evaluated the impact of polypharmacy on HRQoL among Medicare beneficiaries with PC.

METHODS: This observational, retrospective study analyzed data from the Surveillance, Epidemiology and End Results (SEER) Medicare Health Outcomes Survey (MHOS) data resource. Beneficiaries aged ≥65 and enrolled in Medicare Advantage Organizations were included if they had a PC diagnosis and continuously enrolled in Part D for 12 months prior to the completion of MHOS. Polypharmacy was determined based on the unique number of Part D prescriptions during 12 months before survey: no polypharmacy (NP, n=0-4), polypharmacy (PP, n=5-9), and excessive polypharmacy (EPP, n≥10). HRQoL was assessed using the Physical and Mental Component Summary T-scores (PCS and MCS, respectively) in MHOS. ANOVA and Pearson's Chi-Square tests were performed to assess variances between polypharmacy and continuous/categorical variables. Multivariate linear regression models with generalized estimating equations were used to assess the association between polypharmacy and HRQoL. The severely impaired HRQoL cohort was identified based on normalized z-scores of PCS and MCS. Odds ratios were calculated to prioritize drug-drug and class-class pairs impacting HRQoL.

RESULTS: Data from 16,573 beneficiaries (24,126 records) showed that 39.3% had PP and 30.3% had EPP. Beneficiaries with PP and EPP had significantly lower mean PCS and MCS scores compared to those without polypharmacy (p<0.001). After adjusting for covariates, beneficiaries with EPP had clinically significantly lower PCS (-6.95 (-7.32, -6.58)) and MCS (-3.48 (-3.84, -3.12)) compared to the NP group. Analysis of class-class pairs highlighted benzodiazepines and adrenergic beta2-agonists as having a synergistic impact on HRQoL with the highest odds ratio.

CONCLUSIONS: Benzodiazepines and adrenergic beta2-agonists have a synergistic impact on HRQoL among older adults with PC.