Physician assistants and nurse practitioners perform effective roles on teams caring for Medicare patients with diabetes.

One approach to the patient-centered medical home, particularly for patients with chronic illnesses, is to include physician assistants (PAs) and nurse practitioners (NPs) on primary care teams. Using Medicare claims and electronic health record data from a large physician group, we compared outcomes for two groups of adult Medicare patients with diabetes whose conditions were at various levels of complexity: those whose care teams included PAs or NPs in various roles, and those who received care from physicians only. Outcomes were generally equivalent in thirteen comparisons. In four comparisons, outcomes were superior for the patients receiving care from PAs or NPs, but in three other comparisons the outcomes were superior for patients receiving care from physicians only. Specific roles performed by PAs and NPs were associated with different patterns in the measure of the quality of diabetes care and use of health care services. No role was best for all outcomes. Our findings suggest that patient characteristics, as well as patients' and organizations' goals, should be considered when determining when and how to deploy PAs and NPs on primary care teams. Accordingly, training and policy should continue to support role flexibility for these health professionals.