Errors less likely among ICU residents working longer rather than shorter shifts

Residents made more serious errors while working a schedule that eliminated extended shifts, although the results varied by study site and may have been affected by higher workloads on the shorter shifts.

Resident physicians working extended shifts were less likely to make serious errors than those working shorter shifts in a recent study.

Researchers performed a multicenter cluster-randomized crossover trial that compared extended-duration with non-extended-duration shifts among pediatric residents at six U.S. ICUs. Extended-duration schedules included shifts of 24 hours or more and served as the control. In the intervention schedules, extended shifts were eliminated and residents were cycled through day and night shifts of 16 hours or less. Each site began a two-year trial at a different time, with sites paired by start date. One site from each pair was randomly assigned to start with the control schedule while the other started with the intervention schedule. There was a four-month wash-in interval before the study began, followed by eight months of data collection. After another four-month wash-in interval, the sites crossed over to the other schedule, and researchers collected another eight months of data. The study's primary outcome was serious medical errors, as assessed by intensive surveillance that included direct observation and chart review. The study also assessed data on residents' work schedules, sleep, workload, and other factors. Results were published June 25 by the New England Journal of Medicine.

Overall, 172 residents completed 200 rotations on the control schedule, and 188 completed 210 rotations on the intervention schedule. The types of patients in the ICU were similar during each of the two work schedules. However, residents' workload was higher during the intervention schedules than during the control schedules (mean ICU patients per resident, 8.8±2.8 vs. 6.7±2.2, respectively). Residents made more serious errors during the intervention schedules than the control schedules (97.1 vs. 79.0 per 1,000 patient-days; relative risk, 1.53 [95% CI, 1.37 to 1.72]; P<0.001), and there were also more serious errors unitwide (181.3 vs. 131.5 per 1,000 patient-days; relative risk, 1.56 [95% CI, 1.43 to 1.71]). Error rates varied widely by site, with lower rates during the intervention schedules at one site, similar rates at two sites, and higher rates during the intervention schedules at three sites.

The researchers noted that data collection may have varied across sites, that other site-level factors, such as attending supervision, may have influenced their findings, and that their results may not be generalizable to other settings. In addition, a secondary analysis indicated potential confounding by increases in workload with the intervention schedule, although this finding should be considered exploratory, they said. The researchers concluded that residents on ICU rotations in their study were more likely to make serious medical errors while working a schedule that eliminated extended work shifts versus a schedule that included shifts lasting 24 hours or more. They also noted that while residents' workload was heavier on the intervention schedule, their sleep and neurobehavioral performance improved.

“A decade ago, the National Academy of Medicine recommended that resident physician work-hour reduction should not occur without an investment of resources to support adequate staffing and infrastructure. Excessive work hours degrade patient safety, but so too do excessive workloads and poor handoffs,” the authors wrote. “The results of our trial suggest that future interventions to address the persistent patient safety problems in academic health centers must address and rigorously evaluate all these challenges concurrently.”