Association between state Medicaid policies and accrual of Black participants to cancer clinical trials.

Abstract

1501 Background: Black individuals remain underrepresented in U.S. cancer clinical trials, partly due to financial barriers to participation. While coverage of the routine costs of trial participation has long been mandatory for Medicare and the commercially insured, only 16 states have enacted similar mandates for Medicaid enrollees. Given the disproportionate representation of Black individuals in state Medicaid programs, we hypothesized that such mandates may have led to improved accrual of Black participants to cancer clinical trials. Methods: We conducted a retrospective, quasi-experimental study using de-identified data from the ECOG-ACRIN Cancer Research Group to evaluate changes in the accrual of Black participants to cancer clinical trials associated with state-mandated Medicaid coverage of routine trial costs. The study population included non-elderly adults enrolled in therapeutic clinical trials for breast, colorectal, lung, or prostate cancer from 2000-2019. We employed a difference-in-differences approach with event-study specification to compare outcomes in states that mandated Medicaid coverage of routine trial costs relative to states that did not, before and after mandates were enacted. Outcomes included the proportion of trial participants who had Medicaid insurance (vs. non-Medicaid) and the proportion who were Black (vs. non-Black). Models adjusted for age, sex, cancer type, cancer stage, study phase, and study site (community vs. academic). Results: Among 24,321 trial participants (mean age 52.0 [SD 8.2] years, 82.8% female), 7.2% had Medicaid coverage and 10.5% were Black. Compared to states without Medicaid coverage mandates, states with mandates had a statistically significant increase in the proportion of Black trial participants in the first year following the mandate (+6.4 percentage points [95%CI 1.8% to 11.0%]) but not in subsequent years. There was no association between state mandates and the proportion of trial participants enrolled in Medicaid (effects ranged from -0.7 percentage points [95%CI -4.6% to 3.3%] in the first year after mandates to -3.9% [95%CI -8.6% to 0.8%] in the third year). Conclusions: State-mandated Medicaid coverage of the routine costs of trial participation was associated with a short-term increase in the proportion of Black trial participants. These findings suggest that Medicaid policies have the potential to improve representation of racial minority groups in cancer clinical trials, and support recent federal legislation mandating state Medicaid programs to cover trial participation costs as of January 2022. Our study was limited by use of data from only one large cancer research group, focus on only four common cancers, and limited power to analyze the policy impact for other racial and ethnic minority groups. Additional work is needed to replicate these findings in larger cohorts of trial participants.