11050 Background: Palliative care is a specialized medical approach to improve symptoms and quality of life for patients with serious illnesses, including cancer, yet its utilization remains low. While enrollment in Medicare Advantage (MA) has grown and surpassed Traditional Medicare (TM), less is known about differences in palliative care between MA and TM and the extent to which MA plan design, particularly provider networks, contributes to these differences. Methods: Using the 2025 SEER–Medicare linkage, we identified Medicare beneficiaries aged ≥66 years diagnosed with distant-stage breast, colorectal, lung, pancreatic, or prostate cancer between 2016 and 2021. We included patients who survived at least 2 months after diagnosis and had continuous enrollment in TM or MA from 1 year before diagnosis to death/end of follow-up. The primary outcome was the cumulative incidence of palliative care billing within 6 months of diagnosis. To assess the role of provider networks, we first assigned each patient a treating oncologist based on the plurality of visits with cancer diagnosis codes; we then conducted 1:1 matching of patients enrolled in a given MA plan to patients in TM treated by the same oncologists within the same county. Multivariable Cox proportional hazards models estimated differences in palliative care billing between TM and MA overall and by MA plan type, before and after matching, adjusting for sociodemographic and clinical characteristics. Results: Among 135,402 beneficiaries with advanced cancer, 67.7% were enrolled in TM and 32.3% in MA; over half were female, 7.3% Hispanic, and 9.5% non-Hispanic Black. The 6-month cumulative incidence of palliative care billing was 13.3% among MA beneficiaries and 9.3% among TM beneficiaries. In adjusted analyses, MA enrollment was associated with higher palliative care billing (hazard ratio HR, 1.39; 95% CI, 1.34–1.44). When stratified by plan types, palliative care was particularly higher among patients in health maintenance organization (HMO) plans (HR=1.66, 95%CI=1.60-1.72) but not other plan types. After matching on treating oncologists, 23,033 TM and 23,033 MA patients were included. Matched MA beneficaries were less likely to have HMO plans than those not matched (49.1% vs. 76.7%). Differences in palliative care were attenuated and statistically non-significant, with cumulative incidence of 11.0% and 10.4% among MA and TM, and an adjusted hazard ratio of 1.05 (95%CI=0.99, 1.11). Similar attenuation was observed in HMO plans (1.16, 95%CI=1.08, 1.24). Conclusions: Palliative care billing was significantly higher among MA than TM beneficiaries, but these differences were substantially reduced after accounting for provider networks. These findings suggest that between-provider variation accounts for the majority of the difference in palliative care receipt between TM and MA beneficiaries.
Hu et al. (Wed,) studied this question.