Time Dependency in Physician Decision-Making

Using data on more than 250,000 emergency department (ED) visits, we study the time-of-day effect on physician decision-making and patient outcomes. After controlling for patient characteristics, physician fixed effects, and work hours, we find that cases treated at night have significantly lower probability of inpatient admission and involve fewer medical tests. These cases are also more likely to revisit the ED, which supports the decline in physician performance. While we cannot completely rule out the possibility of limited hospital arrangements, our findings are most consistent with the detrimental effect of disrupted circadian rhythms during night shifts.