Access Challenges in Allogeneic Hematopoietic Cell Transplant: Identifying At-Risk US States by Exploring Social Vulnerability, Physician Density, and Unmet Need

PURPOSE Access to allogeneic hematopoietic cell transplantation (alloHCT) is limited by factors beyond physician control. A more complete picture of how barriers to alloHCT overlap is needed to target access-related initiatives. This study examined relationships between social vulnerability index (SVI), physician density (PD), and adult alloHCT unmet need to identify states at-risk of access challenges in the United States. METHODS For this exploratory retrospective analysis, we aggregated SVI, Physician Compare, and 2018-2022 alloHCT unmet need data across all US counties. We defined PD as hematology-oncology/HCT providers per 10,000 population and dichotomized variables into low (≤50%) and high (>50%) percentiles. We identified counties with high SVI and unmet need and low PD as at-risk. Using multivariable linear regression, we assessed influences on unmet need. RESULTS In county-level models across all US counties, lower PD (b = –10.102, P < .001) and higher SVI (b = 13.799, P < .001) predicted higher unmet need, with socioeconomic status (12.295, P < .001) and housing/transportation (b = 4.370, P = .016) vulnerability predicting higher unmet need in sensitivity analysis. States at-risk for access challenges were Texas, North Carolina, Florida, Nevada, and Georgia. At the county-level within at-risk states, only lower PD (–9.888, P < .001) was a significant predictor of higher unmet need. However, in sensitivity analysis, total SVI (13.111, P < .001), race/ethnicity (17.913, P < .001), and housing/transportation (14.164, P < .001) vulnerability were all significant predictors of higher unmet need. CONCLUSION We found relationships among SVI, PD, and alloHCT unmet need to identify states at-risk for access impediments. Data can be examined to allocate resources to overcome barriers to alloHCT, with interventions targeting PD and SVI to improve access and equity in care.