Hematopoietic Cell Transplantation Outcomes among Medicaid and Privately Insured Patients with Sickle Cell Disease

Abstract

Compared with privately insured patients, recipients of Medicaid have been reported to have worse outcomes in several clinical conditions and following various surgical and medical procedures. However, the relationship between health insurance status and allogeneic hematopoietic cell transplantation (alloHCT) outcomes among patients with sickle cell disease (SCD) is not well described. We sought to compare alloHCT outcomes between patients with SCD who underwent alloHCT while enrolled on Medicaid versus those who underwent alloHCT while covered by private health insurance. We conducted a retrospective multicenter study using data reported to the Center for International Blood and Marrow Transplant Research. US patients enrolled on Medicaid or private insurance who underwent a first alloHCT for SCD between 2008 and 2018 were eligible for this study. The primary outcome was event-free survival (EFS), defined as time to death or graft failure. Secondary outcomes included overall survival (OS), graft failure, acute graft-versus-host disease (GVHD), and chronic GVHD. Univariate analysis was performed using the Kaplan-Meier method for EFS and OS. The proportion of patients with graft failure, acute GVHD, and/or chronic GVHD was calculated using the cumulative incidence estimator to accommodate competing risks (ie, death). Cox regression was used to identify factors associated with EFS, OS, graft failure, and acute and chronic GVHD. A total of 399 patients (Medicaid, n = 225; private insurance, n = 174) were included in this study. The median duration of follow-up was 34 months (range, 1.0 to 134.7 months) for the Medicaid group and 38.7 months (range, 0.3 to 139.3 months) for the private insurance group. Compared with the patients with private insurance, those on Medicaid had a significantly lower 3-year EFS (75.4% [95% confidence interval (CI), 69.4% to 81%] versus 82.2% [95% CI, 76.9% to 87.8%]; P = .0279) and a significantly higher 3-year cumulative incidence of graft failure (17.2% [95% CI, 12.5% to 22.5%] versus 10.5% [95% CI, 6.4% to 15.4%]; P = .0372). There were no significant between-group differences in 3-year OS (P = .6337) or in the cumulative incidence of acute GVHD (P = .4556) or chronic GVHD (P = .6878). Cox regression analysis after adjusting for other significant variables showed that the patients enrolled on Medicaid had a lower EFS (hazard ratio [HR], 2.36; 95% CI, 1.44 to 3.85; P = .0006) and a higher cumulative incidence of graft failure (HR, 2.57; 95% CI, 1.43 to 4.60; P = .0015), with no significant between-group differences in OS (HR, 0.99; 95% CI, 0.47 to 2.07; P = .9765), acute GVHD (HR, 0.94; 95% CI, 0.59 to 1.49; P = .7905), or cGVHD (HR, 0.98; 95% CI, 0.65 to 1.48; P = .9331). That EFS is worse in patients on Medicaid compared with privately insured individuals following alloHCT for SCD provides the rationale for research to better understand the mechanisms by which insurance status impacts alloHCT outcomes among patients with SCD.

Keywords: Health disparities; Medicaid; Sickle cell disease.