Abstract PO-188: Racial differences in healthcare utilization among lung cancer patients using immune checkpoint inhibitors: A population-based analysis

Abstract

Abstract Introduction: Although Immune checkpoint inhibitor (ICI) use for lung cancer has rapidly expanded, racial differences and their impact on clinical outcomes has been under-studied. This study addresses a crucial public health priority by evaluating racial disparities in healthcare utilization among patients with lung cancer receiving ICIs. Methods: We utilized the SEER-Medicare linked database with older adult patients (aged ≥65 years) with a diagnosis of lung cancer receiving ipilimumab (ipi), nivolumab (nivo), pembrolizumab and ipi/nivo in combination. Healthcare utilization was defined as emergency room (ER) and non-ER hospitalizations following ICI initiation. Hospitalization events were modeled by Cox proportional hazards regression using the counting process style of input (to incorporate repeated events) to assess the relative risk (RR) of hospitalization by race. The covariates used in the model were age at first ICI, sex, marital status, year of diagnosis, and Charlson comorbidity status. Results: We identified 4,091 lung cancer patients receiving ICIs; of which 3,451 were White, 350 were Black, and 290 were Asian. Following ICI initiation after adjusting for potential confounding, Asians were 13% less likely to experience ER hospitalization than Whites (RR: 0.87, 95% CI: 0.77-0.98; p=0.027), and Blacks were 22% more likely than Whites to experience ER hospitalization (RR: 1.22, 95% CI: 1.10-1.35; p<0.001). For non-ER hospitalization after adjusting for potential confounding, Asians were 38% less likely than Whites to experience non-ER hospitalization (RR: 0.62, 95% CI: 0.45-0.84; p=0.002), however, Blacks were not significantly different from Whites (RR: 0.95, 95% CI: 0.75-1.21; p=0.67). Conclusion: This retrospective observational study is the first to show the racial differences in healthcare utilization among lung cancer patients receiving ICIs. Although ICI use is markedly increasing, our results could suggest that some populations do not experience their benefits equally. Further studies are warranted to validate the study results about the increase in ER and non-ER hospitalizations among blacks. Citation Format: Nikita Nikita, Joshua Banks, Scott W. Keith, Jennifer M. Johnson, Melissa Wilson, Swapnil Sharma, Grace LuYao. Racial differences in healthcare utilization among lung cancer patients using immune checkpoint inhibitors: A population-based analysis [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-188.