Comparison of US Oncologist Rurality by Practice Setting and Patients Served.

Importance: Studies of the oncology workforce most often classify physician rurality by their practice location, but this could miss the true extent of physicians involved in rural cancer care. Objective: To compare a method for identifying oncology physicians involved in rural cancer care that uses the proportion of rural patients served with the standard method based on practice location. Design, Setting, and Participants: This cross-sectional study used retrospective Centers for Medicare & Medicaid Services encounter data on medical oncologists, radiation oncologists, and surgeons treating Medicare beneficiaries diagnosed with breast, colorectal, or lung cancer from January 1 to December 31, 2019. Data were analyzed from May to September 2023. Main Outcomes and Measures: The standard method of classifying oncologist physician rurality based on practice location was compared with a novel method of classification based on proportion of rural patients served. Results: The study included 27 870 oncology physicians (71.3% male), of whom 835 (3.0%) practiced in a rural location. Physicians practicing in a rural location treated a high proportion of rural patients (median, 50.0% [IQR, 16.7%-100%]). When considering the rurality of physicians' patient panels, 5123 physicians (18.4%) whose patient panel included at least 20% rural patients, 3199 (11.5%) with at least 33% rural patients, and 1996 (7.2%) with at least 50% rural patients were identified. Using a physician's patient panel to classify physician rurality revealed a higher number and greater spread of oncology physicians involved in rural cancer care in the US than the standard method, while maintaining high performance (area under the curve, 0.857) and fair concordance (κ, 0.346; 95% CI, 0.323-0.369) with the method based on practice setting. Conclusions and Relevance: In this cross-sectional study, classifying oncologist rurality by the proportion of rural patients served identified more oncology physicians treating patients living in rural areas than the standard method of practice location and may more accurately capture the rural cancer physician workforce, as many hospitals have historically been located in more urban areas. This new method may be used to improve future studies of rural cancer care delivery.