Inequity in selective referral to high-volume hospitals for genitourinary malignancies

Compared to low-volume hospitals, high-volume hospitals are associated with lower rates of perioperative morbidity and mortality. However, access to high-volume hospitals is unequal. We investigated racial and socioeconomic disparities among patients undergoing surgery for genitourinary malignancies at high-volume hospitals.

We queried the National Cancer Database from 2004-2015 to identify patients who underwent radical prostatectomy, radical cystectomy, and nephrectomy for nonmetastatic prostate cancer, muscle-invasive urothelial bladder cancer, and kidney cancer, respectively. Hospitals were ranked based on their annual volume for the given procedure. The endpoint of our study was receipt of treatment at a high-volume hospital. Multivariable logistic regression models were used to identify predictors of treatment at a high-volume hospital.

Our final cohort consisted of 397,242 prostate cancer patients, 39,480 bladder cancer patients, and 292,095 kidney cancer patients. For prostate and bladder cancer, Black race was associated with lower odds of treatment at a high-volume hospital (Odds Ratio [OR] 0.83, 95% confidence interval [CI] 0.79-0.87 and 0.71, 95%CI 0.58-0.87; reference: White). Higher education level and private insurance status were associated with greater odds of treatment across all 3 procedures (strongest effect for prostate cancer; higher education level: OR 1.63 [1.58-1.68]; private insurance 1.86 [1.77-1.97]). Moreover, an interaction was found between race and study period for all cancers examined (P < 0.001). Subgroup analyses revealed that Black patients were more likely to undergo radical prostatectomy at high-volume hospitals in 2013-2015 (OR 0.98, 95%CI 0.94-1.02) compared to 2004-2006 (OR 0.83, 95%CI 0.79-0.87).

Across all procedures, patients with lower education status and lack of insurance were less likely to be treated at high-volume hospitals. For prostate cancer and bladder cancer, Black race was a negative predictor of treatment at high-volume hospitals. Further studies are needed to understand the root causes for this inequity.