Racial differences in survival and healthcare resource utilization among Medicaid-insured adults with metastatic castration-sensitive prostate cancer.

Abstract

26 Background: Racial inequalities in healthcare have long existed in the United States, with Black or African American (BAA) men having higher overall cancer death rates compared to other racial or ethnic groups. One of the greatest disparities is in prostate cancer (PC), which disproportionately affects BAA men, though when matched for stage, whether outcomes differ by race is controversial. This study assessed differences in overall survival (OS) and healthcare resource utilization (HRU) by race in Medicaid-insured patients with metastatic castration-sensitive prostate cancer (mCSPC). Methods: This retrospective longitudinal cohort study evaluated de-identified administrative claims data from the Centers for Medicare and Medicaid Services 100% Medicaid data files, from 01/01/2010 - 12/31/2018. The study included adult patients with a diagnosis for PC, ≥1 claim for androgen deprivation therapy (ADT), diagnosis of metastasis before or within 90 days after ADT, and continuous eligibility for ≥6 months pre-index (defined baseline period) and ≥3 months post-index. The date of first receipt of ADT or first receipt of novel hormonal therapy or docetaxel if initiated within 30 days before ADT defined the index date. OS and HRU were assessed from the index date to the earliest of end of continuous eligibility, data availability, or death. A multivariable Cox proportional hazards model of OS and a multivariable Poisson model of HRU were implemented and controlled for age, plan type, region, median state income, residence in a state with Medicaid expansion, index year, Charlson comorbidity index (CCI), baseline HRU, and clinical characteristics. Results: The study included 1,488 patients with mCSPC (467 [31%] BAA, 446 [30%] White [W], 219 [15%] Hispanic [H], 356 [24%] Other races [O]). H were the oldest (mean age 68 years), followed by O (67 years), W (64 years), and BAA (63 years). BAA and H had the highest CCI (0.6), followed by O (0.5), and W (0.4). Median unadjusted OS was 71.3 months in H, 57.1 months in O, 52.1 months in BAA, and 44.9 months in W. After adjustment, H had significantly lower risk of death compared to W (hazard ratio [95% confidence interval (CI)]: 0.65 [0.43, 0.96]) and BAA patients had comparable survival to W (0.91 [0.69, 1.22]). Adjusted incidence rate ratios (IRR) showed significantly lower incidence of PC-related outpatient (OP) visits for BAA as compared to W (IRR [95% CI]: 0.71 [0.55, 0.99]), per patient per year. The remaining HRU endpoints were not significantly different among racial groups. Conclusions: Among Medicaid-insured adult patients with mCSPC, H were more likely to live longer than W patients. BAA patients had similar survival and lower rates of PC-related OP visits as compared with W, which shows differential use of PC-related healthcare resources between BAA and W.