Utilization and outcome disparities in autologous hematopoietic stem celltransplantation among patients with multiple myeloma in the United States

Abstract

Abstract Background: Hematopoietic cell transplantation (HCT) is a complex and cost-intensive, but life-saving procedure for malignant hematological disorders. Despite advances in the field, and its increased use over time, racial/ethnic disparities in access and outcome exist for minority populations. This study explores the utilizations rates and outcome disparities in HCT among patients with multiple myeloma in the United States. Methods: We identified patients diagnosed with multiple myeloma and those that underwent HCT between 2011-2019 using the nationwide inpatient sample (NIS) database. We compared the racial differences in access to HCT and outcomes post-HCT during the hospitalization, including complications, associated infections, length of stay, and mortality rate. Baseline characteristics were compared using a T-test and Chi-Square. Multivariate logistic regression analysis was applied to estimate racial differences in odds of access and outcomes. We used STATA Version 15.0 Software for data analysis. The p- value was set at p = 0.05 for statistical significance. Results: We conducted a retrospective study of 193,748 patients with a diagnosis of multiple myeloma, out of which 10,094 (5.2%) underwent hematopoietic cell transplant (HCT). African Americans (OR: 0.66, 95% CI: 0.61 – 0.72, p <0.001) and Hispanics (OR: 0.86, 95% CI: 0.78 – 0.96, p =0.005) had lower odds of HCT, while Asians/Pacific Islanders (OR: 1.13, 95% CI: 1.01 – 1.27, p = 0.028) had higher odds of HCT compared to White patients. About 6,137 (60.8%) developed complications, and about 77 (0.80%) died post- HCT during hospitalization. The mean age for HCT was 60.2 years, and the average length of stay was 17 days. In this HCT cohort, 6,365 (65.8%) were Whites, 1,784 (18.4%) were African-Americans, 816 (8.4%) were Hispanics, and 715 (7.4%) were Asians/Pacific Islanders. When compared to Whites, African-Americans had lower odds of in-hospital mortality (OR: 0.26, 95% CI: 0.08 – 0.84, p = 0.024). The odds of mortality were not statistically different between the Hispanics (OR: 0.65, 95% CI: 0.18 – 2.37, p = 0.510), and Asian/Pacific Islanders (OR: 1.88, 95% CI: 0.86 – 4.11, p = 0.113) compared to Whites. African-Americans had lower odds of respiratory failure (OR: 0.33, 95% CI: 0.16 – 0.63, p = 0.001), and septic shock (OR: 0.43, 95% CI: 0.22 – 0.82, p = 0.010) compared to Whites, while the odds of respiratory failure and septic shock were not statistically different between Hispanics and Asians/Pacific Islanders compared to Whites. African-Americans had higher odds of mucositis (OR: 1.28, 95% CI: 1.10 – 1.49, p = 0.001), compared to Whites, while the odds of mucositis were not statistically different between Hispanics and Asians/Pacific Islanders compared to Whites. Hispanics had lower odds of bone marrow failure (BMF) (OR: 0.18, 95% CI: 0.04 – 0.76, p = 0.019) compared to Whites, while the odds of BMF were not statistically different between African-Americans and Hispanics compared to Whites. Asian/Pacific Islanders had higher odds of graft versus host diseases (GVHD) (OR: 2.36, 95% CI: 1.12 – 4.99, p = 0.024) and pancytopenia (OR: 1.37, 95% CI: 1.04 – 1.81, p = 0.023) compared to Whites, while the odds of GVHD, and pancytopenia were not statistically different between African-Americans and Hispanics compared to Whites. There were no statistically significant differences in the odds of bone marrow rejection, neutropenia, clostridium difficile infection (CDI), cytomegalovirus (CMV) infection, and invasive fungal infections among the racial groups. Conclusions: Our study shows that African-Americans and Hispanics with multiple myeloma had lower utilizations rates for HCT, while Asian/Pacific Islanders had higher utilizations rates compared to Whites. African-American had lowers odds of in-hospital mortality post-HCT compared to Whites. African-Americans had lower odds of respiratory failure and septic shock, but higher odds of mucositis compared to Whites. Hispanics had lower odds of BMF compared to Whites. Asians/Pacific-Islanders had higher odds of GVHD and pancytopenia compared to Whites. In conclusion, there are racial disparities in the access to, and outcomes of HCT among patients with multiple myeloma in the US. Efforts to identify and mitigate the barriers to access to HCT among racial/ethnic minorities should be prioritized and intensified in the overall continuum of care for multiple myeloma.