Practice Locations of Michigan Ophthalmologists as a Model to Compare Practice Patterns of DO and MD Surgical Subspecialists.

Context: While existing data demonstrate that osteopathic physicians (ie, DOs) in primary care are more likely than allopathic physicians (ie, MDs) to practice in rural areas, no data exist on practice patterns of DO surgical subspecialists, such as ophthalmologists. Michigan has a relatively high number of DOs and, formerly, the most osteopathic ophthalmology residency programs in the United States. Analyzing the distribution of ophthalmologists in Michigan may reveal patterns and predict trends about the geographic distribution of DO surgical subspecialists across the country.

Objective: To compare geographic distributions of DO and MD ophthalmologists in Michigan and identify differences in community size and type (eg, urbanized area, urban cluster, or rural area) of practice.

Methods: A list of Michigan's ophthalmologists practicing in 2018 was developed using the Centers for Medicare and Medicaid Services, the American Osteopathic College of Ophthalmology, and the American Medical Association data sets. DOs and MDs were then analyzed by determining where each ophthalmologist practiced, identifying the size and type of community in which they practiced, and finally by comparing the percentage of DOs and MDs who practiced in various community sizes and each community type as defined by the US Census Bureau. A χ2 analysis was used to determine whether a difference existed in practice locations.

Results: A total of 643 ophthalmologists practiced in Michigan in 2018, including 85 DOs and 558 MDs. A greater proportion of DOs worked in rural areas and urban clusters (57 [67%]), whereas a greater proportion of MDs worked in urbanized areas (368 [66%]). Of DOs, 28 (33%) practiced in cities with a population of at least 50,000 vs 371 MDs (66%). Fourteen DOs (16%) practiced in communities with a population of at least 100,000 vs 207 MDs (37%). χ2 analysis showed a significant difference in the geographic distribution of ophthalmologist DOs and MDs (P<.01).

Conclusion: Higher proportions of DOs practice ophthalmology in smaller, more rural Michigan communities compared with MDs, implying that a subgroup exists that tends to serve underserved areas.