ObjectiveFee-for-service payment may motivate physicians to see more patients and achieve higher productivity. In 2015, emergency physicians at one Vancouver hospital switched to fee-for-service payment, while those at a sister hospital remained on contract, creating a natural experiment where the compensation method changed, but other factors remained constant. Our hypothesis was that fee-for-service payment would increase physician efficiency and reduce patient wait times.MethodsThis interrupted time series with concurrent control analysed emergency department (ED) performance during a 42-week period, encompassing the intervention (fee for service). Data were aggregated by week and plotted in a time series fashion. We adjusted for autocorrelation and developed general linear regression models to assess level and trend changes. Our primary outcome was the wait time to physician.ResultsData from 142,361 ED visits were analysed. Baseline wait times rose at both sites during the pre-intervention phase. Immediately post-intervention, the median wait time increased by 2.4 minutes at the control site and fell by 7.2 minutes at the intervention site (difference=9.6 minutes; 95% confidence interval, 2.9-16.4;p=0.007). The wait time trend (slope) subsequently deteriorated by 0.5 minutes per week at the intervention site relative to the expected counterfactual (pfor the trend difference=0.07). By the end of the study, cross-site differences had not changed significantly from baseline.ConclusionFee-for-service payment was associated with a 9.6-minute (24%) reduction in wait time, compatible with an extrinsic motivational effect; however, this was not sustained, and the intervention had no impact on other operational parameters studied. Physician compensation is an important policy issue but may not be a primary determinant of ED operational efficiency.