Article Text
Abstract
Introduction Black patients have lower bladder cancer survival rates than White patients, but previous studies have not been able to explain this difference. Recent work has found that racial disparities in bladder cancer survival persist after adjusting for sex, age, and tumour characteristics. The objective of this study was to assess the association of insurance status, comorbidities, marital status, the receipt of radical cystectomy and being qualified for federal assistance (a marker for low individual-level SES) with disparities in bladder cancer survival.
Methods We identified 15 666 (592 Black and 15 074 White) bladder cancer cases diagnosed between 1992 and 1999 (follow-up through 2003) from the SEER-Medicare database, and constructed relative survival models to assess 5-year survival disparities.
Results The relative survival ratios (RSR) for Black patients vs White patients were as follows: unadjusted, RSR 2.22 (95% CI 1.90 to 2.59), adjusting for year of diagnosis, registry, age, sex, stage, and grade, RSR 1.54 (95% CI 1.32 to 1.81); additionally adjusting for comorbidity score, marital status, and receipt of radical cystectomy, RSR 1.45 (95% CI 1.25 to 1.70); additionally adjusting for SES, RSR 1.26 (95% CI 1.08 to 1.48). Lower comorbidity score, being married, higher SES and receipt of radical cystectomy were independently associated with increased bladder cancer survival.
Conclusions Racial disparities persist after adjusting for comorbidity score, marital status, receipt of radical cystectomy and SES in this insured population. As the SES variable used in this study does not capture the diversity across the SES gradient and it is strongly associated with race, further studies investigating the influence of SES and its correlates may provide further explication of this disparity.