Treatment Initiation Among Black and White Older Adults With Multiple Myeloma: A SEER ‐Medicare Analysis

BACKGROUND: This study aims to describe time to treatment initiation for Black and White older adults with multiple myeloma (MM), and to test the hypothesis that Black/White disparities in treatment initiation have increased over time. METHODS: Black and White older adults (65+) diagnosed with myeloma 2007-2017 were identified in the SEER-Medicare database. Continuous Medicare Parts A/B coverage 12 months before and after diagnosis or until death, and Part D coverage for 12 months following diagnosis or until death were required for inclusion. We explored time to treatment initiation by race across three diagnosis time periods (2007-10, 2011-2014, 2015-2017) using Cox proportional hazard models. We estimated cumulative incidence of treatment initiation by race at 3, 6, and 12 months after diagnosis for all time periods. RESULTS: White MM patients were more likely to initiate treatment than Black MM patients across time periods. Hazard ratios (HR) and 95% confidence intervals (CI) ranged from HR = 1.35 (95% CI: 1.25, 1.46) to HR = 1.36 (95% CI: 1.27, 1.44). Black/White differences in the cumulative incidence of treatment initiation at 3, 6, and 12 months were also significant and persistent across time periods, ranging from 0.09 (95% CI: 0.02, 0.15) to 0.11 (95% CI: 0.05, 0.17). Contrary to our hypothesis, Black/White disparities were not increasing over time. CONCLUSION: Our results suggest that Black patients initiate MM treatment later than White patients and are less likely to ever initiate treatment. Contrary to our hypothesis, Black/White disparities are not increasing over time and have remained static.