Change in Functional Status After Prostate Cancer Treatment Among Medicare Advantage Beneficiaries

Abstract

ObjectiveTo examine the relationship between treatment and subsequent functional status among prostate cancer patients. MethodsUsing Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey data, we identified men 65 years or older diagnosed with prostate cancer between 1998 and 2009 (follow-up through 2010) who were treated with conservative management, surgery, or radiation. Our primary outcome was functional status as measured by activities of daily living. Secondary outcomes included physical component summary and mental component summary scores, which are both calculated from the Short Form 36 (SF-36) and the Veterans RAND 12-item health survey (VR-12) questionnaires. We included patients who completed 2 surveys and performed propensity score analyses to match patients 1:5 with noncancer controls. We used generalized linear mixed effects models, accounting for clustering due to insurance plan. ResultsWe identified 408 patients of whom 143 (35%) underwent conservative management, 59 (14%) underwent surgery, and 206 (51%) underwent radiation. Among conservative management and radiation patients, changes in functional status mirrored that of their noncancer controls (all P > .05). Among surgery patients, changes in activities of daily living scores were not significant, but physical component summary (mean difference = 4.5, P < .001) and mental component summary (mean difference = 3.3, P = .01) scores declined slightly more than for their noncancer peers. ConclusionSurgery patients had a slight decline in their general functional status whereas conservative management and radiation patients had no differences in functional status compared with their noncancer peers. Although the functional status of surgery patients declined more than that of their noncancer peers, this difference may not be clinically significant.