Summary
There are two degree programs for licensed physicians in the U.S.: allopathic medical doctorate (MD) and osteopathic doctorate (DO). However, evidence is limited as to whether outcomes differ between patients treated by MD vs DO surgeons.
Researchers evaluate differences in surgical outcomes and practice patterns by surgeon medical school training (MD vs DO). This study used 100% Medicare claims data from inpatient hospitals providing surgical services from January 1, 2016, to December 31, 2019 among Medicare fee-for-service beneficiaries aged 65 to 99 years who underwent 1 of the 14 most common surgical procedures. Data analysis was performed from January 17, 2023, to August 13, 2024.
The primary outcome was 30-day mortality, and the secondary outcomes were readmissions and length of stay. To assess differences between surgeons by medical school training, a multivariable linear probability model was used, which was adjusted for hospital fixed effects and patient, procedure, and surgeon characteristics.
Findings: Of the 2,360,108 total surgical procedures analyzed, 2,154,562 (91.3%) were performed by MD surgeons, and 205,546 (8.7%) were performed by DO surgeons. Of 43,651 total surgeons, most surgeons were MDs (39,339 or 90.1%), the median age was 49.0 years, and 6,649 surgeons (15.2%) were female. The mean age of patients undergoing surgical procedures was 74.9 years, 1, 353,818 of 2,360,108 patients (57.4%) were female, and 2,110,611 patients (89.4%) self-reported as white.
DO surgeons were significantly more likely to operate on older patients, female patients, and Medicaid dual-eligible patients. DOs performed a lower proportion of elective operations and were more likely to work in public hospitals and nonteaching hospitals. There was no evidence that 30-day mortality differed between MD and DO surgeons. On secondary analyses, no difference was found in 30-day readmissions or length of stay between MD and DO surgeons.
In this retrospective cohort study using Medicare data, there was no evidence that patient outcomes differed between MD and DO surgeons for common operations after adjusting for patient factors and practice settings.