Sleep and Alertness in a Duty-Hour Flexibility Trial in Internal Medicine.

BACKGROUND: A purpose of duty-hour regulations is to reduce sleep deprivation in medical trainees, but their effects on sleep, sleepiness, and alertness are largely unknown. METHODS: We randomly assigned 63 internal-medicine residency programs in the United States to follow either standard 2011 duty-hour policies or flexible policies that maintained an 80-hour workweek without limits on shift length or mandatory time off between shifts. Sleep duration and morning sleepiness and alertness were compared between the two groups by means of a noninferiority design, with outcome measures including sleep duration measured with actigraphy, the Karolinska Sleepiness Scale (with scores ranging from 1 [extremely alert] to 9 [extremely sleepy, fighting sleep]), and a brief computerized Psychomotor Vigilance Test (PVT-B), with long response times (lapses) indicating reduced alertness. RESULTS: Data were obtained over a period of 14 days for 205 interns at six flexible programs and 193 interns at six standard programs. The average sleep time per 24 hours was 6.85 hours (95% confidence interval [CI], 6.61 to 7.10) among those in flexible programs and 7.03 hours (95% CI, 6.78 to 7.27) among those in standard programs. Sleep duration in flexible programs was noninferior to that in standard programs (between-group difference, -0.17 hours per 24 hours; one-sided lower limit of the 95% confidence interval, -0.45 hours; noninferiority margin, -0.5 hours; P = 0.02 for noninferiority), as was the score on the Karolinska Sleepiness Scale (between-group difference, 0.12 points; one-sided upper limit of the 95% confidence interval, 0.31 points; noninferiority margin, 1 point; P<0.001). Noninferiority was not established for alertness according to the PVT-B (between-group difference, -0.3 lapses; one-sided upper limit of the 95% confidence interval, 1.6 lapses; noninferiority margin, 1 lapse; P = 0.10). CONCLUSIONS: This noninferiority trial showed no more chronic sleep loss or sleepiness across trial days among interns in flexible programs than among those in standard programs. Noninferiority of the flexible group for alertness was not established. (Funded by the National Heart, Lung, and Blood Institute and American Council for Graduate Medical Education; ClinicalTrials.gov number, NCT02274818.).

Use of the psychomotor vigilance test to aid in the selection of risk controls in an air medical transport operation.

Study Objectives: This study evaluated the utility and ecological validity of the 3-minute psychomotor vigilance test (PVT) completed by safety-critical personnel in an air medical transport operation as part of a fatigue risk management program. Methods: Crewmembers in an air medical transport operation self-administered an alertness assessment incorporating a 3-minute PVT at different time points during their duty schedule. The prevalence of alertness deficits was evaluated based on a failure threshold of 12 errors considering both lapses and false starts. To evaluate the ecological validity of the PVT, the relative frequency of failed assessments was evaluated relative to crewmember position, timing of the assessment within the duty schedule, time of day, and sleep quantity in the last 24 h. Results: 2.1% of assessments were associated with a failing PVT score. Crewmember position, timing of assessment within the duty shift, time of day, and sleep quantity in the last 24 h were found to affect the relative frequency of failed assessments. Obtaining less than 7-9 h of sleep was associated with systematic increases in the failure rate (F[1, 54 612] = 168.1, p < .001). Obtaining less than 4 h of sleep was associated with a frequency of a failed assessment 2.99 times higher than the frequency of a failed assessment when obtaining 7-9 h of sleep. Conclusions: Results provide evidence for the utility and ecological validity of the PVT as well as the suitability of the PVT failure threshold to support fatigue risk management in safety-critical operations.

Sleep and Alertness Among Interns in Intensive Care Compared to General Medicine Rotations: A Secondary Analysis of the iCOMPARE Trial.

BACKGROUND: Medical interns are at risk for sleep deprivation from long and often rotating work schedules. However, the effects of specific rotations on sleep are less clear. OBJECTIVE: To examine differences in sleep duration and alertness among internal medicine interns during inpatient intensive care unit (ICU) compared to general medicine (GM) rotations. METHODS: This secondary analysis compared interns during a GM or ICU rotation from a randomized trial (2015-2016) of 12 internal medicine residency programs assigned to different work hour limit policies (standard 16-hour shifts or no shift-length limits). The primary outcome was sleep duration/24-hour using continuous wrist actigraphy over a 13-day period. Secondary outcomes assessed each morning during the concomitant actigraphy period were sleepiness (Karolinska Sleepiness Scale [KSS]), alertness (number of Brief Psychomotor Vigilance Test [PVT-B] lapses), and self-report of excessive sleepiness over past 24 hours. Linear mixed-effect models with random program intercept determined associations between each outcome by rotation, controlling for age, sex, and work hour policy followed. RESULTS: Of 398 interns, 386 were included (n = 261 GM, n = 125 ICU). Average sleep duration was 7.00±0.08h and 6.84±0.10h, and number of PVT lapses were 5.5±0.5 and 5.7±0.7 for GM and ICU, respectively (all P > .05). KSS was 4.8±0.1 for both rotations. Compared to GM, ICU interns reported more days of excessive sleepiness from 12am-6am (2.6 vs 1.7, P < .001) and 6am-12pm (2.6 vs 1.9, P = .013) and had higher percent of days with sleep duration < 6 hours (27.6% vs 23.4%, P < .001). GM interns reported more days with no excessive sleepiness (5.3 vs 3.7, P < .001). CONCLUSIONS: Despite ICU interns reporting more excessive sleepiness in morning hours and more days of insufficient sleep (<6 hours), overall sleep duration and alertness did not significantly differ between rotations.

Use of the Psychomotor Vigilance Test in Fitness for Work Assessments.

OBJECTIVE: The objective of the pilot program was to evaluate the utility of the psychomotor vigilance test (PVT) in aiding clinicians in making fitness for work determinations. METHODS: A 10-minute PVT was incorporated into fitness for work examinations by occupational health staff at two integrated refining/petrochemical plants. Based on all evidence from the clinical examination, including PVT results, clinicians made their fitness for work determination. RESULTS: Employees who were determined to be fit for work had significantly fewer PVT errors than did employees determined to be unfit for work or fit for work with limitations, with t(98) = -14.71, P < 0.001. CONCLUSIONS: The pilot assessed a new application of the PVT as an adjunct to occupational health evaluations focused on determining fitness for work. Results demonstrated that the PVT can be a valuable tool for this purpose.