Background: Provider experience, or clinical volume, is associated with improved outcomes in many complex healthcare settings. Despite increased complexity of anticancer therapies, studies evaluating physician-level experience and cancer treatment outcomes are lacking. Methods: A population-based study was conducted of older adults (aged ≥66 years) diagnosed with B-cell non-Hodgkin’s lymphoma in 2004 through 2011 using SEER-Medicare data. Analysis focused on outcomes in patients receiving rituximab, the first approved monoclonal anticancer immunotherapy. We hypothesized that lower physician experience using rituximab and managing its infusion-related reactions would be associated with early treatment discontinuation. A 12-month look-back from each initiation of rituximab was used to categorize physician volume (0, 1–2, or ≥3 initiations per year). Modified Poisson regression was used to account for provider-level correlation and estimated relative risk (RR) of early rituximab discontinuation (<3 cycles within 180 days of rituximab initiation). Cox proportional hazards were used to measure the impact of rituximab discontinuation on survival. Results: Among 15,110 patients who initiated rituximab with 2,684 physicians, 7.6% experienced early rituximab discontinuation. Approximately one-fourth of patients (26.1%) initiated rituximab with a physician who had no rituximab initiations during the preceding 12 months. Compared with patients treated by physicians who had ≥3 rituximab initiations in the prior year, those treated by physicians without initiations were 57% more likely to experience early discontinuation (adjusted RR [aRR], 1.57; 95% CI, 1.35–1.82; P<.001 for 0 vs ≥3, and aRR, 1.19; 95% CI, 1.03–1.37; P=.02 for 1–2 vs ≥3). Additionally, rituximab discontinuation was associated with higher risk of death (adjusted hazard ratio, 1.39; 95% CI, 1.28–1.52; P<.001). Conclusions: Lower oncologist experience with rituximab was associated with increased risk of early rituximab discontinuation in Medicare beneficiaries with non-Hodgkin’s lymphoma. Physician-level volume may be an important factor in providing high-quality cancer care in the modern era.
Submitted December 17, 2018; accepted for publication April 26, 2019.
Previous presentation: A portion of this work was presented at the 2017 ASCO Annual Meeting on June 5, 2017.
Author contributions:Study concept and design: Huntington, Davidoff. Data acquisition, analysis, and interpretation: All authors. Manuscript preparation: All authors. Critical revision: All authors.
Disclosures: Dr. Huntington has disclosed that he received consulting fees/honoraria from Celgene, Janssen, Genentech, and AbbVie. Dr. Zeidan has disclosed that he has received consulting fees/honoraria from Ariad, Gilead, Incyte, Celgene, AbbVie, and Pfizer, and received grant/research support from Celgene, AbbVie, Pfizer, Medimmune/AstraZeneca, Incyte, and Takeda. Dr. Gross has disclosed that he has received grant/research support from Pfizer and Johnson & Johnson. The remaining authors have disclosed that they have not received any financial considerations from any person or organization to support the preparation, analysis, results, or discussion of this article.
Funding: This project was supported by a pilot grant from the Yale Comprehensive Cancer Center, Yale School of Medicine. This publication was made possible by CTSA grant KL2 TR001862 from the National Center for Advancing Translational Science (NCATS), a component of the NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NIH. Dr. Zeidan is supported in part by the NCI (award P30 CAO16359).
Correspondence: Scott F. Huntington, MD, MPH, MSc, Department of Internal Medicine, Section of Hematology, Yale University, 333 Cedar Street, PO Box 208028, New Haven, CT 06520-8028. Email: firstname.lastname@example.org