Dispelling the myth: comparable duration and impact of research training for MD-PhD and PhD graduates

The average time to degree for completing a life sciences PhD in the United States is longer for single-degree than dual-degree trainees, supporting a perception that the PhD training of MD-PhDs is less rigorous or fulsome. To determine whether degree format influences the duration and impact of graduate training, we analyzed data for the 2011-2016 graduates of 3 Harvard Medical School PhD programs. Linear mixed effects models were used to determine the association between degree type (MD-PhD vs. PhD) and research outcomes, including time to degree, time to thesis defense, and publications submitted during the PhD. Although pursuing an MD-PhD was associated with a 1.5-year shorter time to PhD degree, basing this calculation on the official PhD period does not account for completion of early PhD requirements, including research rotations and qualifying coursework, during the first 2 years of medical school. There was no association between degree format and total number of first-author or overall publications, though pursuing a dual degree was associated with increased impact metrics of published papers. The results highlight that despite the seemingly shorter PhD durations of MD-PhD graduates based on graduate program enrollment period, research training is on par with their single-degree peers, rendering MD-PhD graduates well equipped to become successful scientific investigators.