Effects of socioeconomic status (SES) and healthcare resource (HCR) availability on survival in Black patients (pts) versus (vs) White pts with multiple myeloma (MM): A SEER Medicare analysis.

Abstract

e13678 Background: In MM, disparities exist for overall survival (OS) by race, and many factors may contribute to these differences. This study evaluates whether SES and HCR availability impacts OS in older pts with newly diagnosed MM (NDMM) based on race. Methods: This retrospective study used linked SEER-Medicare claims (diagnosis [Dx] 6/1/2013–12/31/2017) and Area Health Resource Files (AHRFs; from 2018) to identify non-Hispanic White and non-Hispanic Black pts aged ≥66 years with NDMM. AHRFs included county-level HCR availability data (e.g. number of long-term hospital beds, medical doctors [MDs]). Continuous Medicare A and B enrollment until 12/31/2019 or preceding death was required. Pts with other cancers, Dx from death data, missing county information and enrollment in health maintenance organizations or clinical trials were excluded. Kaplan-Meier was used for unadjusted median OS and Cox proportional hazards for OS risk by race. Age, sex, race, Charlson Comorbidity Index (CCI), poverty, education, and HCR availability were included in the adjusted mixed effects Cox model. Results: We identified 6,609 pts with NDMM; 15.6% were Black. For Black pts vs White pts, median age at Dx was 76 vs 77 years, 57.1% vs 46.0% were female, and mean CCI was 2.1 vs 1.4 (p<.001 for all). Within census tracts, mean percentage of pts living under the poverty line and received <12 years of education was 21.2% vs 11.3% (p<.001) and 19.0% vs 11.3% (p<.001) for Black pts vs White pts, respectively. Unadjusted median OS for Black pts vs White pts was 2.76 vs 3.01 years (hazard ratio [HR]: 1.08; p=.063). In the adjusted model, several SES and HCR availability factors were significant. OS HR by race reversed directionality when adjusted for demographics, SES and HCR availability, but this was not significant (HR: 0.92; p=.12; Table). Conclusions: We found that Black pts with NDMM in SEER-Medicare claims were younger, had higher CCI, completed less education, and were more likely to live in census tracts with higher poverty percentages vs White pts. Several factors relating to SES and HCR availability significantly influenced OS and may drive disparities in care. Further research on larger datasets is needed to better understand these disparities. [Table: see text]