Disparities in bladder cancer survival by race/ethnicity and gender are likely related to differences in diagnosis. We assessed disparities in stage at diagnosis and potential contributing factors within a large, integrated delivery system.
We conducted a retrospective cohort study of 7244 patients with bladder cancer age ≥ 21 years diagnosed from January 2001 to June 2015 within Kaiser Permanente Southern California. Bivariate analyses compared stage at diagnosis - as well as comorbidities, health plan membership length, and health care utilization prior to diagnosis - by race/ethnicity, gender, and age. Multivariable generalized linear mixed models with urologist as a random effect were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for diagnosis of muscle-invasive bladder cancer (MIBC) versus non-muscle-invasive bladder cancer.
In multivariable analyses, stage at diagnosis varied significantly by race/ethnicity (P < .001). Non-Hispanic black patients had significantly higher odds of being diagnosed with MIBC than non-Hispanic white patients (OR, 1.33; 95% CI, 1.05-1.67), whereas Asian patients had significantly lower odds (OR, 0.67; 95% CI, 0.49-0.91). Women were significantly more likely to be diagnosed with MIBC than men (OR, 1.40; 95% CI, 1.22-1.61). Non-Hispanic black women had the highest proportion (39%) of MIBC diagnoses. Among Hispanic and Asian patients, a greater proportion of diagnoses occurred at younger ages.
Health care coverage within an equal-access system did not eliminate disparities in stage at diagnosis by race/ethnicity or gender. Studies are needed to identify etiologic factors and aspects of care delivery (eg, patient-physician interactions) that may affect the diagnostic process to inform efforts to improve health equity.
Clinical genitourinary cancer. 2019 Sep 12 [Epub ahead of print]
Kim N Danforth, Tiffany Q Luong, David K Yi, Ayae Yamamoto, Aniket A Kawatkar, Philip H Kim, Ronald K Loo, Margo A Sidell, Stephen G Williams
Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA. Electronic address: ., Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA., Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA; Department of Quality and Risk Management, Kaiser Foundation Hospital and Health Plan, Pasadena, CA., Department of Urology, Southern California Permanente Medical Group, San Diego, CA., Department of Urology, Southern California Permanente Medical Group, Downey, CA., Department of Urology, Southern California Permanente Medical Group, Riverside, CA.