Opportunities for Maintenance of Certification to Better Reflect Scope of Practice Among Medical Oncologists.

Purpose: Critics argue that the American Board of Internal Medicine's medical oncology Maintenance of Certification examination requires medical oncologists with a narrow scope of practice to spend time studying material that is no longer relevant to their practice. However, no data are available describing the scope of practice for medical oncologists.

Methods: Using Medicare claims, we examined the scope of practice for 9,985 medical oncologists who saw 8.6 million oncology conditions in 2016, each of which was assigned to 1 of 23 different condition groups. Scope of practice was then measured as the percentage of oncology conditions within each of the 23 groups. We grouped physicians with similar scopes of practice by applying K-means clustering to the percentage of conditions seen. The scope of practice for each physician cluster was determined from the cancers that encompassed the majority of average oncology conditions seen among physicians composing the cluster.

Results: We found 20 distinct scope-of-practice clusters. The largest (n = 6,479 [65.5%]) had a general oncology scope of practice. The remaining physicians focused on a narrow scope of cancers, including 22.6% focused on ≥ 1 solid tumors and 11.9% focused on hematologic malignancies. The largest focused cluster accounted for 7.7% of physicians focused on breast cancer.

Conclusion: A single American Board of Internal Medicine Maintenance of Certification assessment in medical oncology is most appropriate for approximately 65% of certified medical oncologists' practices. However, the addition of assessments focused on breast cancer and hematologic malignancies could increase this figure to upwards of 85% of certified medical oncologists.