Fatigue management strategies for physician trainees have been widely debated since implementation of the 2003 ACGME duty hour standards that for the first time limited work hours for physicians. A 2009 Institute of Medicine report recommended protected sleep periods for medicine trainees on extended overnight shifts, but they have never been shown to be feasible in teaching hospital settings.
To determine whether a protected sleep period of 5 hours is feasible and effective in increasing the time slept by interns on extended duty overnight shifts, we conducted 2 randomized controlled trials in parallel: one at the Philadelphia Veterans Affairs Medical Center, the other at the Hospital of the University of Pennsylvania. We examined the effect of a protected sleep period on interns' sleep, measures of behavioral alertness, and patient outcomes. In year 1 we tested a 5-hour protected sleep period and in year 2 a 3-hour protected sleep period.
Between July 2009 and June 2010 (Year 1) and July 2010 and June 2011 (Year 2), interns and senior medical student subinterns (henceforth all referred to as interns) were randomized to serve on either an internal medicine rotation at the Philadelphia VA Medical Center, on the oncology unit of the Hospital of the University of Pennsylvania, or at both institutions, with subinterns only serving at the VA center.
On the first day of each 4-week rotation interns were given a light and motion sensitive wrist actigraph for continuously tracking rest-activity patterns. Data from the actigraphs were collected in 1-minute epochs and stored in the watch until downloaded at the end of each rotation. Study participants were asked to complete a validated 3-minute psychomotor vigilance test (PVT) on designated laptops located throughout the service each morning between 6 AM and 8 AM when they were at the hospital and every night they were on call between 11 PM and midnight. The PVT measured alertness based on reaction time to stimuli presented at random 2- to 5-second intervals. Participants also filled out electronic sleep logs, which contained questions about patient workload and sleep disruptions as well as the Karolinska sleepiness scale (KSS).
Twelve 4-week blocks were randomly assigned to either a standard intern schedule (extended duty overnight shifts of up to 30 hours; equivalent to 1200 overnight intern shifts at each site), or a protected sleep period (protected time from 12:30 AM to 5:30 AM with handover of work cell phone; equivalent to 1200 overnight intern shifts at each site). Participants were asked to wear wrist actigraphs and complete sleep diaries. Interns were required to hand over hospital-provided work cell phones to the covering night float resident and encouraged to sleep in a bed in a dark quiet room. If urgent assistance was required, night float residents were instructed to wake the interns. Given the higher acuity for the oncology service, an extra resident was scheduled to assist with cross-coverage and admissions from 11 PM to 7 AM. In Year 2 the protected time was staggered between 12:00 AM - 3:00 AM or 3:00 AM -6:00 AM and there was no additional covering resident at the university hospital to make the intervention personnel neutral..
In both years, the primary outcome was sleep time during the protected sleep period as measured by actigraph wrist activity monitors and supplemented by self-reported electronic sleep diaries. Secondary outcomes were sleep time during the entire overnight extended duty shift, mean sleep amount within the 4-day call cycle, percentage of on-call nights without sleep, length of time awake before sleep onset during or after overnight call shifts, response speed and number of lapses on the PVT in the morning postcall, subjective reports of sleepiness (KSS score), whether sleep during on-call nights was disturbed, and patient outcomes. To address feasibility, night float residents were called each morning by study staff to report time of work cell-phone handoff and retrieval. Patient outcomes assessed included length of stay, transfer to the medical intensive care unit, 30-day readmission rates, and mortality among patients who were newly admitted to the studied services. Patient care data came from the university hospital patient file and the VA patient treatment file
In Year 1, for 98.3% of on-call nights, cell phones were signed out as designed. At the VA center, participants with protected sleep periods had a mean 2.86 hours (95% CI, 2.57-3.10 hours) of sleep vs 1.98 hours (95% CI, 1.68-2.28 hours) among those who did not have protected sleep periods (P < .001). At the university hospital, participants with protected sleep had a mean 3.04 hours (95% CI, 2.77-3.45 hours) of sleep vs 2.04 hours (95% CI, 1.79-2.24) among those who did not have protected sleep (P < .001). Participants with protected sleep were significantly less likely to have call nights with no sleep: 5.8% (95% CI, 3.0%-8.5%) vs 18.6% (95% CI, 13.9%-23.2%) at the VA center (P < .001) and 5.9% (95% CI, 3.1%-8.7%) vs 14.2% (95% CI, 9.9%-18.4%) at the university hospital (P = .001). Participants felt less sleepy after on-call nights in the intervention group, with Karolinska sleepiness scale scores of 6.65 (95% CI, 6.35-6.97) vs 7.10 (95% CI, 6.85-7.33; P = .01) at the VA center and 5.91 (95% CI, 5.64-6.16) vs 6.79 (95% CI, 6.57-7.04; P < .001) at the university hospital. While participants who received protected sleep periods were more alert on the morning post-call than their control group counterparts, there were no differences in patient outcomes between standard schedule months vs. intervention months.
In Year 2, on 97.4% of intern on call nights cell phones were signed out as designed. Interns at HUP had significantly longer sleep durations during both protected periods compared to controls (HUP early shift: 2.40 vs. 1.55 hours, p < 0.0001; HUP late shift: 2.44 vs. 1.55 hours, p < 0.0001). At PVAMC sleep duration was longer only for the late shift group (PVAMC late: 2.40 vs 1.90 hrs, p < 0.0001). At both sites, interns assigned to either protected period were significantly less likely to have call nights with no sleep (PVAMC early shift: 6% vs. 21%, p <0.0001; PVAMC late shift: 10% vs. 21%, p = 0.014; HUP early shift: 12% vs. 23%, p = 0.01; HUP late shift: 11% vs. 23%, p = 0.005). PVT response speed was significantly faster in the intervention group after on-call nights at the PVAMC but not at HUP. There were no differences in patient outcomes between standard schedule months vs. intervention months.
In the past decade, the ACGME has twice modified duty hour standards for physicians in training, with these changes motivated by an interest in reducing fatigue among house staff, reducing the rate of medical errors, and improving quality of care. The most recent duty hour standards, implemented in July 2011, were motivated by a 2009 congressionally mandated IOM report which concluded that to minimize fatigue-related errors a protected sleep period of 5 hours during any work shift beyond 16 hours duration should be required.
This study is the first to demonstrate that protected sleep periods are feasible and do increase amount slept by residents on call, reduce the amount of prolonged wakefulness, and increase cognitive performance. The question about how to optimally manage fatigue for physicians in training is particularly important for the care Veterans receive within the VA health care system because 70% of VA hospitals are teaching hospitals. The 16 hour shift length limit which was mandated by the ACGME for all interns starting in July of 2011 has raised questions about discontinuity of care and the impact on both residency education and quality of care. We are having discussions with the ACGME about obtaining a waiver for wider scale effectiveness study testing of protected sleep periods as an alternative to 16 hour shifts, as this approach may provide a better balance in terms of fatigue management and continuity of care than the approach currently being used at VA and other hospitals throughout the United States.The reduction in the rate of prolonged wakefulness is particularly important, as continuous wakefulness of periods of more than 21 hours is a major predictor of performance errors. Also, to our knowledge only 2 previous studies have evaluated the feasibility of deploying a pager-free sleep period at night during extended duty shifts. In both studies, the protected sleep period was not mandatory, resulting in relatively low adherence to the protected sleep period schedule. For example, in 1 study only 22% of interns signed out their own patients to the cross-covering resident during protected periods. In contrast, adherence to the protected period was 98.3% in our intervention. In addition, the frequency of disruptions was much lower in the intervention group for both services. Making protected sleep periods a standard part of the internship schedule as opposed to a research protocol likely provided a level of social norming that would have been difficult to achieve as part of a research protocol.
The protected sleep period also afforded residents approximately twice as many sleep durations of 3 hours or more as the control condition-a duration associated with greater recovery of performance and alertness. The same was seen at the other end of the spectrum. Interns who received protected sleep periods were less likely to have on-call nights with no sleep. Although it is not clear how large these benefits need to be to offset the cost and effort of implementing a 5-hour protected sleep period, studies have found significant benefits for alertness and performance with even modest increases in nap sleep duration, and we were able to confirm this for both psychomotor speed and for subjectively assessed sleepiness. These findings are consistent with other evidence that obtaining more sleep during prolonged duty can reduce fatigue. Although the protected sleep periods interns undertook during the intervention were associated with reduced sleepiness and better vigilance performance, we had no evidence that they were associated with either positive or negative changes in patient outcomes, which was limited by insufficient power to reliably detect such changes. This study indicates that protected sleep periods during prolonged duty are feasible, likely to increase the amount of uninterrupted sleep interns obtain during extended duty overnight shifts, reduce the number of 24-hour periods awake, and improve behavioral alertness in the morning following on-call nights. Although there is evidence that obtaining sleep (relative to no sleep) during prolonged duty helps reduce fatigue and that the amount of fatigue reduction increases with the amount of sleep, from this study we do not have evidence that this is also associated with improvements in patient outcomes. A rigorous comparative effectiveness analysis of protected sleep times vs 16-hour shifts in improving intern alertness and cognitive function and patient outcomes could have a significant effect in leading to nationwide changes in duty hour regulation for all physicians in training. To the extent that protected sleep periods are feasible and improve alertness, they may provide a reasonable alternative to mandated shorter shifts.
External Links for this Project
- Shea JA, Dinges DF, Small DS, Basner M, Zhu J, Norton L, Ecker AJ, Novak C, Bellini LM, Dine CJ, Mollicone DJ, Volpp KG. A randomized trial of a three-hour protected nap period in a medicine training program: sleep, alertness, and patient outcomes. Academic Medicine. 2014 Mar 1; 89(3):452-9. [view]
- Volpp KG, Shea JA, Small DS, Basner M, Zhu J, Norton L, Ecker A, Novak C, Bellini LM, Dine CJ, Mollicone DJ, Dinges DF. Effect of a protected sleep period on hours slept during extended overnight in-hospital duty hours among medical interns: a randomized trial. JAMA. 2012 Dec 5; 308(21):2208-17. [view]
- Halpern SD, Kohn R, Dornbrand-Lo A, Metkus T, Asch DA, Volpp KG. Lottery-based versus fixed incentives to increase clinicians' response to surveys. Health services research. 2011 Oct 1; 46(5):1663-74. [view]
- Norton L, Volpp KG, Shea JA, Zhu J, Small D, Basner M, Ecker A, Dinges D, Mollicone D, Novak C, Bellini L. A randomized controlled trial of the feasibility of a protected sleep period for medical interns in the hospital for prolonged duty. Paper presented at: Society of General Internal Medicine Annual Meeting; 2012 May 10; Orlando, FL. [view]
- Volpp KG, Shea JA, Small DS, Basner M, Zhu J, Norton L, Ecker A, Novak C, Bellini LN, Dinges DF. A randomized controlled trial of the feasibility of a protected sleep period for medical interns in the hospital for prolonged duty. Poster session presented at: VA HSR&D / QUERI National Meeting; 2012 Jul 18; National Harbor, MD. [view]
- Volpp KG. Duty hour regulation for residents: what we know and future directions. Paper presented at: American Academy of Sleep Medicine Annual Meeting; 2009 Jun 5; Seattle, WA. [view]
Prevention, Treatment - Comparative Effectiveness
Education Research, Research method, Safety