Effect on Patient Safety of a Resident Physician Schedule without 24-Hour Shifts

Abstract

Background: The effects on patient safety of eliminating extended-duration work shifts for resident physicians remain controversial.

Methods: We conducted a multicenter, cluster-randomized, crossover trial comparing two schedules for pediatric resident physicians during their intensive care unit (ICU) rotations: extended-duration work schedules that included shifts of 24 hours or more (control schedules) and schedules that eliminated extended shifts and cycled resident physicians through day and night shifts of 16 hours or less (intervention schedules). The primary outcome was serious medical errors made by resident physicians, assessed by intensive surveillance, including direct observation and chart review.

Results: The characteristics of ICU patients during the two work schedules were similar, but resident physician workload, described as the mean (±SD) number of ICU patients per resident physician, was higher during the intervention schedules than during the control schedules (8.8±2.8 vs. 6.7±2.2). Resident physicians made more serious errors during the intervention schedules than during the control schedules (97.1 vs. 79.0 per 1000 patient-days; relative risk, 1.53; 95% confidence interval [CI], 1.37 to 1.72; P<0.001). The number of serious errors unitwide were likewise higher during the intervention schedules (181.3 vs. 131.5 per 1000 patient-days; relative risk, 1.56; 95% CI, 1.43 to 1.71). There was wide variability among sites, however; errors were lower during intervention schedules than during control schedules at one site, rates were similar during the two schedules at two sites, and rates were higher during intervention schedules than during control schedules at three sites. In a secondary analysis that was adjusted for the number of patients per resident physician as a potential confounder, intervention schedules were no longer associated with an increase in errors.

Conclusions: Contrary to our hypothesis, resident physicians who were randomly assigned to schedules that eliminated extended shifts made more serious errors than resident physicians assigned to schedules with extended shifts, although the effect varied by site. The number of ICU patients cared for by each resident physician was higher during schedules that eliminated extended shifts. (Funded by the National Heart, Lung, and Blood Institute; ROSTERS ClinicalTrials.gov number, NCT02134847.).

Figure 1.. Participants and Rotations.

The control schedules included shifts of 24 hours or more; the intervention schedules eliminated extended shifts and cycled residents through day and night shifts of 16 hours or less. Of resident physicians who completed more than 1 rotation, 58 completed 2 rotations, 5 completed 3 rotations, and 3 completed 4 rotations. The 333 resident physicians who completed 410 rotations include 27 participants who rotated through at least one control and one intervention cycle.

Figure 2 (facing page).. Serious Errors, Adverse Events, and Near Misses by Site and Schedule.

The control schedules included shifts of 24 hours or more; the intervention schedules eliminated extended shifts and cycled resident physicians through day and night shifts of 16 hours or less. The relative risk is for the intervention schedule as compared with the control schedule. Panel A shows the relative risk of serious medical errors, both resident-physician–related (primary outcome) and unitwide, Panel B the relative risk of preventable adverse events, and Panel C the relative risk of near misses.