Using the Natural Experiment Study Design to Evaluate the Effect of a Change in Doctor’s Roster on Patient Flow in an Emergency Department

The effect of changes in doctors’ rosters is rarely subjected to scientific evaluation. We describe how a natural experiment (NE) study design can be used to evaluate if a managerial decision about doctors’ rosters has an effect on patient flow in an emergency department (ED). We hypothesized that an extra doctor each morning from 6 a.m. (i.e., a modified “casino shift”) might improve the productivity of a hospital’s ED