Objective To investigate the variation in the rate of state medical board physician disciplinary actions between US states.

Methods Longitudinal study of state medical board physician disciplinary action rates using the US National Practitioner Data Bank and American Medical Association estimates of physician demographics across all 50 states and the District of Columbia from 2010 to 2014. Results were reliability adjusted using a multilevel logistic model controlling for year of disciplinary action, physicians per capita in each state and the rate of malpractice claims per physician in each state.

Results From 2010 to 2014, there were a total of 5046 506 physician licensure years present. Medical boards reported a total of 21 647 disciplinary actions, of which 5137 (23.7%) were major disciplinary actions involving revocation, suspension or surrender of licence. The mean, reliability-adjusted rate of all disciplinary actions was 3.76 (95% CI 3.21 to 4.42) with a significant variation between states. State rates ranged from 2.13 (95% CI 1.86 to 2.45) to 7.93 (95% CI 6.33 to 9.93) actions per 1000 physicians. The mean rate of major disciplinary actions was 2.71 (95% CI 1.93 to 3.82), ranging from 0.64 (95% CI 0.53 to 0.76) to 2.71 (95% CI 1.93 to 3.82) actions per 1000 physicians. The correlation between the rate of major disciplinary action and minor disciplinary actions was 0.34.

Conclusions There is a significant, fourfold variation in the annual rate of medical board physician disciplinary action by state in the USA. When indicated, state medical boards should consider policies aimed at improving standardisation and coordination to provide consistent supervision to physicians and ensure public safety.