Perioperative Intravesical Chemotherapy for Patients WithNon–Muscle-invasive Bladder Cancer: Understanding the Extent of and Sources of Variation in Guideline-recommended Use

Abstract Objective To examine intravesical chemotherapy (IVC) use according to non–muscle-invasive bladder cancer patient disease risk, and the contributions of multilevel factors to variation in proficient use among patients with low-intermediate disease. Methods This study included 988 patients diagnosed with non–muscle-invasive bladder cancer in an integrated health system in Northern California from 2015-2017. We calculated IVC receipt by disease risk, and among patients with low-intermediate risk disease, assessed the relationship between multilevel factors and IVC receipt using a logistic regression model with random intercepts for provider and service area, and patient-, provider-, and service area-level fixed effects. We further assessed the association of provider- and service area-level factors with IVC use by examining intraclass correlation coefficients. Results Similar proportions of low-intermediate (36%) and high-risk (34%) patients received IVC. In the multivariate analysis, including low-intermediate risk patients, service area volume was strongly and statistically significantly associated with IVC use (adjusted odds ratio, high- vs low-volume: 0.08, 95% Confidence Interval: 0.01-0.58). Provider- and service area-level intraclass correlation coefficients were large, (38%, P  = .0009 and 39% P  = .03, respectively) indicating that much of the variance in IVC use was explained by factors at these levels. Conclusion Our findings highlight opportunities to improve proficient use of IVC. Future research should assess provider- and practice-level barriers to IVC use among low-intermediate risk patients.