OBJECTIVES: The methods used to attribute patients under a value based health care system has important implications with respect to how a practice is measured and performs as well as how individual physicians are evaluated within that practice.

METHODS: Integra Connect evaluated patient attribution results for 7 practices participating in the Centers for Medicare and Medicaid Services (CMS) Oncology Care Model program (OCM), including the number of Evaluation & Management (E&M) services by type and physician specialty, what practice the physician was associated with who prescribed or delivered the chemotherapy medications, patient cancer type, number of co-morbidities, management of complications, and how attribution influenced enhanced practice payments as well as performance metrics.

RESULTS: Our research found that using the plurality of E&M visits alone does not attribute all actively treated cancer patients to oncology practices as many patients who received cancer treatment from the practice were not associated with that provider. Further, attribution varied significantly by cancer type and the number of patient co-morbidities. As a general rule, patients received oncology care from a single practice with that medical specialty. However, even though their oncology medications were prescribed by an oncologist, patients with cancer types like hormone-receptor-positive breast cancer who had fewer oncology office visits were more often attributed to other specialists or their primary care physician. The number of co-morbidities also determined patient practice attribution.

CONCLUSIONS: Specialty practices need to develop a better understanding of how and which patients are attributed to their practices, evaluate the impact that the attribution method has on their performance, and identify ways to maximize the assignment of patients to their practice for whom they provide care. As a practical matter, it might also behoove practices to reserve (and not accrue) a portion of the enhanced payment revenues until the final CMS reconciliation, unless this is solved prospectively.