Healthcare Access Domains and Treatment as Mediators of Ovarian Cancer Racial Disparities in Survival: A Structural Equation Modeling Analysis in SEER-Medicare.

Abstract

Racial differences in healthcare access (HCA) may contribute to disparities in ovarian cancer (OC) survival. We used structural equation models (SEM) to examine associations between race and HCA domains (affordability, availability, accessibility) in relation to overall and OC-specific mortality. Non-Hispanic (NH)-Black and non-Black (Hispanic, NH-White) women diagnosed with OC in 2008-2015 were identified from SEER-Medicare. Cox proportional hazards regression was used to conduct mediation analysis for associations between race and HCA domains with overall and OC-specific mortality. SEM models adjusting for demographic and clinical covariates were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). A total of 4,629 eligible OC patients were identified, including 255 (5.5%) patients who were NH-Black. In SEM adjusting for demographic, clinical, and HCA latent variables, there was a total effect of NH-Black race on overall (HR: 1.11, 95% CI: 1.03,1.19) and OC-specific mortality (HR: 1.16, 95% CI: 1.08, 1.24), which was primarily driven by a direct effect. There was a modest indirect association between NH-Black race and mortality through decreased treatment receipt, though not through HCA. There is a need for studies investigating additional social and biological mechanisms that contribute to worse cancer survival among NH-Black patients.