Effects on resident work hours, sleep duration, and work experience in a randomized order safety trial evaluating resident-physician schedules (ROSTERS)

The increasing authorship trend in neuroscience: A scientometric analysis across 11 countries

Previous studies have demonstrated an increasing trend of the number of authors across various fields over the years. This trend has been attributed to the necessity for larger collaborations and, at times, to ethical issues regarding authorship attribution. Our study focuses on the evolution of authorship trends in the field of Neuroscience. We conducted our analysis based on a dataset containing 580,782 neuroscience publications produced from 2000 to 2022, focusing on the publications within the Group of ten (G10) countries. Using a matrix-based methodology, we extracted and analyzed the average number of authors per country. Our findings reveal a consistent rise in authorship across all G10 countries over the past two decades. Italy emerged with the highest average number of authors, while France stood out for experiencing the most significant increase, particularly in the last decade. The countries with the lowest number of authors per publication were the USA, UK and Canada. Differences between countries could result from variations in the size of collaboration between researchers in different countries. Additionally, these differences may depend on utilitarian considerations aimed at receiving higher scores in the individual evaluation of their own work. We propose that a normalization procedure for the number of authors should be implemented to ensure a fair evaluation of researchers.

Predicting neurobehavioral performance of resident physicians in a Randomized Order Safety Trial Evaluating Resident-Physician Schedules (ROSTERS)

OBJECTIVES

Mathematical models of human neurobehavioral performance that include the effects of acute and chronic sleep restriction can be key tools in assessment and comparison of work schedules, allowing quantitative predictions of performance when empirical assessment is impractical.

METHODS

Using such a model, we tested the hypothesis that resident physicians working an extended duration work roster, including 24-28 hours of continuous duty and up to 88 hours per week averaged over 4weeks, would have worse predicted performance than resident physicians working a rapidly cycling work roster intervention designed to reduce the duration of extended shifts. The performance metric used was attentional failures (ie, Psychomotor Vigilance Task lapses). Model input was 169 actual work and sleep schedules. Outcomes were predicted hours per week during work hours spent at moderate (equivalent to 16-20 hours of continuous wakefulness) or high (equivalent to ≥20 hours of continuous wakefulness) performance impairment.

RESULTS

The model predicted that resident physicians working an extended duration work roster would spend significantly more time at moderate impairment (p = .02, effect size=0.2) than those working a rapidly cycling work roster; this difference was most pronounced during the circadian night (p < .001). On both schedules, performance was predicted to decline from weeks 1 + 2 to weeks 3 + 4 (p < .001), but the rate of decline was significantly greater on extended duration work roster (p < .01). Predicted performance impairment was inversely related to prior sleep duration (p < .001).

CONCLUSIONS

These findings demonstrate the utility of a mathematical model to evaluate the predicted performance profile of schedules for resident physicians and others who experience chronic sleep restriction and circadian misalignment.

Adapting shift work schedules for sleep quality, sleep duration, and sleepiness in shift workers

BACKGROUND

Shift work is associated with insufficient sleep, which can compromise worker alertness with ultimate effects on occupational health and safety. Adapting shift work schedules may reduce adverse occupational outcomes.

OBJECTIVES

To assess the effects of shift schedule adaptation on sleep quality, sleep duration, and sleepiness among shift workers.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, and eight other databases on 13 December 2020, and again on 20 April 2022, applying no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and non-RCTs, including controlled before-after (CBA) trials, interrupted time series, and cross-over trials. Eligible trials evaluated any of the following shift schedule components. • Permanency of shifts • Regularity of shift changes • Direction of shift rotation • Speed of rotation • Shift duration • Timing of start of shifts • Distribution of shift schedule • Time off between shifts • Split shifts • Protected sleep • Worker participation We included studies that assessed sleep quality off-shift, sleep duration off-shift, or sleepiness during shifts.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of the records recovered by the search, read through the full-text articles of potentially eligible studies, and extracted data. We assessed the risk of bias of included studies using the Cochrane risk of bias tool, with specific additional domains for non-randomised and cluster-randomised studies. For all stages, we resolved any disagreements by consulting a third review author. We presented the results by study design and combined clinically homogeneous studies in meta-analyses using random-effects models. We assessed the certainty of the evidence with GRADE.

MAIN RESULTS

We included 11 studies with a total of 2125 participants. One study was conducted in a laboratory setting and was not considered for drawing conclusions on intervention effects. The included studies investigated different and often multiple changes to shift schedule, and were heterogeneous with respect to outcome measurement. Forward versus backward rotation Three CBA trials (561 participants) investigated the effects of forward rotation versus backward rotation. Only one CBA trial provided sufficient data for the quantitative analysis; it provided very low-certainty evidence that forward rotation compared with backward rotation did not affect sleep quality measured with the Basic Nordic Sleep Questionnaire (BNSQ; mean difference (MD) -0.20 points, 95% confidence interval (CI) -2.28 to 1.89; 62 participants) or sleep duration off-shift (MD -0.21 hours, 95% CI -3.29 to 2.88; 62 participants). However, there was also very low-certainty evidence that forward rotation reduced sleepiness during shifts measured with the BNSQ (MD -1.24 points, 95% CI -2.24 to -0.24; 62 participants). Faster versus slower rotation Two CBA trials and one non-randomised cross-over trial (341 participants) evaluated faster versus slower shift rotation. We were able to meta-analyse data from two studies. There was low-certainty evidence of no difference in sleep quality off-shift (standardised mean difference (SMD) -0.01, 95% CI -0.26 to 0.23) and very low-certainty evidence that faster shift rotation reduced sleep duration off-shift (SMD -0.26, 95% CI -0.51 to -0.01; 2 studies, 282 participants). The SMD for sleep duration translated to an MD of 0.38 hours' less sleep per day (95% CI -0.74 to -0.01). One study provided very low-certainty evidence that faster rotations decreased sleepiness during shifts measured with the BNSQ (MD -1.24 points, 95% CI -2.24 to -0.24; 62 participants). Limited shift duration (16 hours) versus unlimited shift duration Two RCTs (760 participants) evaluated 80-hour workweeks with maximum daily shift duration of 16 hours versus workweeks without any daily shift duration limits. There was low-certainty evidence that the 16-hour limit increased sleep duration off-shift (SMD 0.50, 95% CI 0.21 to 0.78; which translated to an MD of 0.73 hours' more sleep per day, 95% CI 0.30 to 1.13; 2 RCTs, 760 participants) and moderate-certainty evidence that the 16-hour limit reduced sleepiness during shifts, measured with the Karolinska Sleepiness Scale (SMD -0.29, 95% CI -0.44 to -0.14; which translated to an MD of 0.37 fewer points, 95% CI -0.55 to -0.17; 2 RCTs, 716 participants). Shorter versus longer shifts One RCT, one CBA trial, and one non-randomised cross-over trial (692 participants) evaluated shorter shift duration (eight to 10 hours) versus longer shift duration (two to three hours longer). There was very low-certainty evidence of no difference in sleep quality (SMD -0.23, 95% CI -0.61 to 0.15; which translated to an MD of 0.13 points lower on a scale of 1 to 5; 2 studies, 111 participants) or sleep duration off-shift (SMD 0.18, 95% CI -0.17 to 0.54; which translated to an MD of 0.26 hours' less sleep per day; 2 studies, 121 participants). The RCT and the non-randomised cross-over study found that shorter shifts reduced sleepiness during shifts, while the CBA study found no effect on sleepiness. More compressed versus more spread out shift schedules One RCT and one CBA trial (346 participants) evaluated more compressed versus more spread out shift schedules. The CBA trial provided very low-certainty evidence of no difference between the groups in sleep quality off-shift (MD 0.31 points, 95% CI -0.53 to 1.15) and sleep duration off-shift (MD 0.52 hours, 95% CI -0.52 to 1.56).

AUTHORS' CONCLUSIONS

Forward and faster rotation may reduce sleepiness during shifts, and may make no difference to sleep quality, but the evidence is very uncertain. Very low-certainty evidence indicated that sleep duration off-shift decreases with faster rotation. Low-certainty evidence indicated that on-duty workweeks with shift duration limited to 16 hours increases sleep duration, with moderate-certainty evidence for minimal reductions in sleepiness. Changes in shift duration and compression of workweeks had no effect on sleep or sleepiness, but the evidence was of very low-certainty. No evidence is available for other shift schedule changes. There is a need for more high-quality studies (preferably RCTs) for all shift schedule interventions to draw conclusions on the effects of shift schedule adaptations on sleep and sleepiness in shift workers.

The Effects of Shift Work on the Immune System: A Narrative Review

Working a shift work schedule has been hypothesized to have negative effects on health. One such described consequence is altered immune response and increased risk of infections. Former reviews have concluded that more knowledge is needed to determine how shift work affects the immune system. Since the last review focusing on this subject was published in 2016, new insight has emerged. We performed a search of the topic in PubMed, Scopus and Embase, identifying papers published after 2016, finding a total of 13 new studies. The articles identified showed inconsistent effect on immune cells, cytokines, circadian rhythms, self-reported infections, and vaccine response as a result of working a shift schedule. Current evidence suggests working shifts influence the immune system, however the clinical relevance and the mechanism behind this potential association remains elusive. Further studies need to include longitudinal design and objective measures of shift work and immune response.

[Physician working hours and effects on health, satisfaction and healthcare]

Changes in the working environment with respect to innovative working time models are also increasingly affecting patient care. The number of physicians working part-time, for example, is continuously rising. At the same time, a general increase in chronic diseases and multimorbid conditions as well as the growing shortage of medical staff, leads to more workload and dissatisfaction among this profession. This short overview summarizes the current study situation and associated consequences regarding working hours of physicians and gives a first explorative overview of possible solutions.

Medical shift work: a narrative review

Shift and night work combine training and practice in medical education, assuming an essential character in some medical specialties. Nevertheless, it is recognized that this work schedule affects biological functions, cognitive performance, and the safety of both patients and workers. The aim of this narrative literature review was to describe current knowledge about the impact of shift and night work in medical professionals. The LILACS, MEDLINE, and SciELO databases were searched for publications between 2010 and 2020 using the terms: "shift work schedule" and "physicians". A total of 12 publications reported outcomes on sleep quality, family relationships, burnout syndrome, and cardiovascular health. Despite these outcomes, the studies highlighted the importance of shift and night work in medical training, reflecting a loss of learning opportunities when limitations are placed on work hours. The studies suggested initiatives to mitigate the effects of shift work, including increased awareness by managers, a culture of respect for resting periods, the encouragement of family support networks, and the availability of natural light in the workplace.

Resident duty hours and resident and patient outcomes: Systematic review and meta-analysis

OBJECTIVES

The policies regarding resident physician work hours are constantly being evaluated and changed. However, the results of randomised control trials (RCTs) are mixed. This systematic review of RCTs aims to synthesise the evidence associated with resident duty hour restrictions and its impact on resident- and patient-based outcomes.

METHODS

A comprehensive search of the Cochrane Library, EMBASE and PubMed was conducted from inception until 31 July 2020. Any RCT evaluating the impact of longer resident physician work hours compared to shorter resident physician work hours on resident- and patient-based outcomes was eligible for inclusion. Two reviewers extracted data independently. The primary outcome was the impact of resident duty hour restrictions on emotional exhaustion, depersonalisation and personal accomplishment, as defined by the Maslach Burnout Inventory. The secondary patient-related outcomes were patient hospital length of stay, serious medical errors and preventable adverse events. Data were pooled using a random-effects model.

RESULTS

Of the 873 references, nine RCTs met the inclusion criteria. A shorter shift length compared with longer shift length was associated with significantly less emotional exhaustion (standardised mean difference [SMD] = -0.11, 95% CI = -0.21, -0.00) and less dissatisfaction with overall well-being (OR = 0.61, 95% CI 0.38, 0.99) but not with hospital length of stay (SMD = -0.01, 95% CI = -0.05, 0.02, p = 0.45) and serious medical errors per 1000 patient hours (OR = 1.07, 95% CI = 0.52, 2.21; p = 0.86).

CONCLUSIONS

Shorter resident duty hours is possibly associated with improvement in resident-based outcomes, specifically, emotional exhaustion, dissatisfaction with overall well-being, sleep duration and sleepiness. These findings may inform the policy change in support of reduced shift hours resulting in overall well-being for the residents with possible reduction in burnout without adverse impact on patient-based outcomes.

Insomnia-A Systematic Review and Comparison of Medical Resident's Average Off-Call Sleep Times

Sleep deprivation is known to have serious consequences, including a decrease in performance, attention and neurocognitive function. It seems common knowledge that medical residents are routinely sleep deprived, yet there is little objective research recording their average sleep times. To discern whether residents may be suffering from the abovementioned side effects, this review aimed to analyze their average sleep times. Thirty papers recording the average sleep time of medical residents were found via a literature search using the key words "resident" and "sleep". An analysis of the mean sleep times cited therein revealed a range of sleep from 4.2 to 8.6 h per night, the median being 6.2 h. A sub-analysis of papers from the USA showed barely any significant differences in sleep time between the specialties, but the mean sleep times were below 7 h. The only significant difference (p = 0.039) was between the mean sleep times of pediatric and urology residents, with the former achieving less sleep. The comparison of methods for data collection showed no significant difference in the sleep times collected. The results of this analysis imply that residents are regularly sleep deprived and may therefore suffer from the abovementioned consequences.

Resting and Recharging: A Narrative Review of Strategies to Improve Sleep During Residency Training

BACKGROUND

Residency involves demanding training with long hours that may cause fatigue and sleep deprivation and adversely impact residents and patients under their care.

OBJECTIVE

To identify, using a narrative review, evidence-based interventions to reduce the physiologic effects of fatigue and sleep deprivation from overnight and night shift work.

METHODS

A PubMed literature search was conducted through August 30, 2021, using the terms "resident" and "sleep" in the title or abstract and further narrowed using a third search term. Observational studies, randomized controlled trials, systematic reviews, and meta-analyses of human subjects written and published in English were included. Studies that were not specific to residents or medical interns or did not investigate an intervention were excluded. Additional studies were identified by bibliography review. Due to the heterogeneity of study design and intervention, a narrative review approach was chosen with results categorized into non-pharmacological and pharmacological interventions.

RESULTS

Initially, 271 articles were identified, which were narrowed to 28 articles with the use of a third search term related to sleep. Bibliography review yielded 4 additional articles. Data on interventions are limited by the heterogeneity of medical specialty, sample size, length of follow-up, and reliance on self-report. Non-pharmacological interventions including strategic scheduling and sleep hygiene may improve sleep and well-being. The available evidence, including randomized controlled trials, to support pharmacological interventions is limited.

CONCLUSIONS

Non-pharmacological approaches to mitigating fatigue and sleep deprivation have varying effectiveness to improve sleep for residents; however, data for pharmacological interventions is limited.

Factors associated with habitual sleep duration in US adults with hypertension: a cross-sectional study of the 2015-2018 National Health and Nutrition Examination Survey

Background

The relationship between inadequate sleep duration and hypertension risk has been established in the general population, but there is a gap in the literature on predictors of habitual sleep duration in adults with hypertension. This study examined factors associated with habitual sleep duration among adults with hypertension in the United States (US).

Methods

Data of 5660 adults with hypertension were obtained by combining the 2015–2018 cycles of the National Health and Nutrition Examination Survey (NHANES). Survey weighted multinomial logistic regression models were fit to examine factors associated with short (< 7 h) and long (> 9 h) sleep duration with adequate sleep duration (7–9 h) as the reference.

Results

The prevalence of self-reported adequate sleep duration was 65.7%, while short sleep duration was 23.6%, and long sleep duration 10.7%. Short sleep duration (compared to adequate sleep duration) was positively associated with history of seeking help for sleeping difficulties (relative risk ratio [RRR], 1.25; 95% confidence interval [CI], 1.02–1.53), Non-Hispanic Black race/ethnicity (RRR, 2.08; 95% CI, 1.61–2.67), working ≥45 h/week (RRR, 1.81; 95% CI, 1.32–2.48), and negatively associated with older age ≥ 65 years (RRR, 0.63; 95% CI, 0.45–0.91) and female gender (RRR, 0.70; 95% CI, 0.56–0.88). Long sleep duration was positively associated with female gender (RRR, 1.24; 95% CI, 1.001–1.54), chronic kidney disease (RRR, 1.48; 95% CI, 1.14–1.92), moderate depressive symptoms (RRR, 1.62; 95% CI, 1.08–2.44), moderately severe to severe depressive symptoms (RRR, 1.89; 95% CI, 1.05–3.43), being in retirement (RRR, 3.46; 95% CI, 2.18–5.49), and not working due to health reasons (RRR, 4.87; 95% CI, 2.89–8.22) or other reasons (RRR, 3.29; 95% CI, 1.84–5.88).

Conclusion

This population-based study identified factors independently associated with habitual sleep duration in adults with hypertension. These included help-seeking for sleeping difficulty, gender, age, chronic kidney disease, depressive symptoms, race/ethnicity, and employment status. These findings can help in the development of tailored approaches for promoting adequate sleep duration in adults with hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12465-2.

Long-term impact of overnight shiftwork implementation on pediatric residents' mental wellness: A repeated cross-sectional survey

Objectives

The Japanese government partially enacted the “Work Style Reform Bill” in 2019. The National Center for Child Health and Development (NCCHD) introduced an Overnight Call Shift (OCS) system for pediatrician training. We conducted a follow‐up survey in 2019 to investigate the long‐term effectiveness of the OCS system to improve the pediatric residents' mental wellness at NCCHD.

Methods

We conducted a questionnaire‐based cross‐sectional survey for pediatric residents in 2019 to compare the data with those of the previous survey in 2012. The questionnaire includes demographic data, working conditions data, and mental wellness assessment by the Center for Epidemiologic Studies Depression scale (CES‐D) and the Maslach Burnout Inventory (MBI).

Results

The collection rate for the 2019 survey was 94.5% (37 participants/39 eligible). Compared to 2012, there were no significant changes in demographic data and working hours, a significant increase by about 30% in residents who took daytime off after night work, about 10% decrease in residents who scored 16 and above on the CES‐D, and a significant decrease in the mean score for depersonalization (DP) in the MBI. Multiple regression analyses showed that daytime off after night work was the decreasing factor for CES‐D and Emotional exhaustion (EE).

Conclusions

The overnight shiftwork system shortened the pediatric residents' duty hours somewhat, and imposed an impact on the pediatric residents' mental wellness.

Are elite track and field athletes on track? The impact of COVID-19 outbreak on sleep behavior and training characteristics

The Covid-19 outbreak forced many governments to enter a nationwide lockdown. The aim of this study was to evaluate, by means of a survey, changes in sleep parameters and physical activity characteristics of elite track and field athletes in three periods: before the lockdown (T0), during the lockdown (09th March – 03rd May 2020, T1) and the first month after the lockdown (T2). This study was conducted from May 2020 to June 2020 and data were collected using an offline survey with 89 elite track and field athletes (mean age: 24.7 ± 5.4; n = 43 males; n = 46 females). The survey consisted of demographic data and questions on physical activity and sleep behavior at T0, T1 and T2. Athletes reported lower sleep quality scores at T1 compared to T0 and T2 (p < 0.0001) and registered delayed bedtime, wake-up time and longer sleep latency during the lockdown compared to pre-lockdown and post-lockdown whereas no changes in total sleep time were reported. No inter-group differences were detected in sleep characteristics between short- and long-term disciplines and between genders. The weekly training volume decreased from 16.1 ± 5.7 hours at T0 to 10.7 ± 5.7 hours at T1 (p < 0.0001) whereas no significant differences were detected in training volume during the lockdown in relation to the square footage of the house (p = 0.309). Alcohol (p = 0.136) and caffeine intake (p = 0.990) and use of electronic devices (p = 0.317) were similar pre-, during, and post-lockdown. The unprecedented circumstances of the Covid-19 pandemic had negative impacts on the Italian track and field athletes’ sleep and training volumes.

Objective Assessment of Sleep Patterns among Night-Shift Workers: A Scoping Review

In this scoping review of the literature, we identified the types and the parameters of objective measurements to assess sleep patterns among night-shift workers. We conducted a literature search using electronic databases for studies published from 1991 to 2020 and charted and summarized key information. We included 32 studies in the review. Polysomnography was used in 6 studies and wearable sleep detection devices were utilized in 26 studies. The duration of sleep assessment using the wearable devices ranged from 1 day to ≥4 weeks, and more than half of the studies collected data for >2 weeks. The majority of the studies used subjective questionnaires, such as the Karolinska Sleepiness Scale, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index, in addition to objective sleep measurements. Total sleep time was the most common parameter, followed by sleep efficiency, sleep onset latency, and time or frequency of being awake. As the utilization of wearable devices to assess the sleep patterns of night-shift workers is expected to increase, further evaluation of device accuracy and precision, optimal data collection period, and key parameters is warranted.

Association of working hour characteristics and on-call work with risk of short sickness absence among hospital physicians: A longitudinal cohort study

Physicians often work long hours and on-call shifts, which may expose them to circadian misalignment and negative health outcomes. However, few studies have examined whether these working hour characteristics, ascertained using objective working hour records, are associated with the physicians' risk of sickness absence. We investigated the associations of 14 characteristics of payroll-based working hours and on-call work with the risk of short sickness absence among hospital physicians. In this cohort study, 2845 physicians from six Finnish hospital districts were linked to electronic payroll-based records of daily working hours, on-call duty and short (1-3 days) sickness absence between 2005 and 2019. A case-crossover design was applied using conditional logistic regression with the 28 day case and control windows to estimate odds ratios (ORs) and 95% confidence intervals (CI) for short sickness absence. After controlling for weekly working hours and the number of normal (≤12 h) shifts, a higher number of long (>12 h) shifts (ORs for ≥5 versus none: 2.54, 95% CI 1.68-3.84), very long (>24 h) shifts (ORs for ≥5 versus none: 2.62, 95%CI 1.61-4.27), and on-call shifts (OR for ≥5 versus none: 2.15, 95% CI 1.44-3.21) and a higher number of short (<11 h) shift intervals (OR for ≥5 versus none: 12.61, 95% CI 8.88-17.90) were all associated with the increased risk of short sickness absence. These associations did not differ between male and female physicians or between age groups. To conclude, the findings from objective working hour records show that long work shifts, on-call shifts and short shift intervals are related to the risk of short (1-3 days) sickness absence among hospital physicians.

Loss of nocturnal dipping pattern of skin sympathetic nerve activity during and following an extended-duration work shift in residents in training

BACKGROUND

Extended-duration work shifts (EDWSs) might affect the health of physician residents, causing autonomic alteration. Skin sympathetic nerve activity (SKNA) recorded by noninvasive neuro-electrocardiography (neuECG) is used to estimate cardiac sympathetic tone. In this study, we aim to evaluate the impact of EDWSs on nocturnal SKNA assessed in resident doctors.

METHODS

Twenty-four residents working EDWSs and 12 PhD students not working nightshift schedules were prospectively recruited. The neuECG was performed between 12 am and 6 am for 5 consecutive nights. SKNA was filtered from neuECG recorded signals. The questionnaires regarding work stress and sleep quality, blood pressure, and salivary alpha-amylase and cortisol levels were administered.

RESULTS

The hours of weekly working and sleep opportunities were similar between residents and students, while residents reported more work stress and worse sleep quality. In residents, SKNA at 6 am (SKNA_6am) was significantly higher than SKNA_2am during the precall night, revealing a dipping pattern. However, the SKNA dipping disappeared during the on-call night and prominently flattened during the first postcall night, the full recovery of which was delayed until the second postcall nights. The morning blood pressure and salivary alpha-amylase and cortisol levels were similar between the precall and postcall days. In contrast, SKNA in students exhibited a constant dipping profile for all recorded nights.

CONCLUSIONS

In healthy young adults, SKNA presents a dip night. The SKNA dip is impaired by working a nightshift, with a delayed recovery. The neuECG might serve as a useful tool to detect subclinical autonomic disturbances in shiftworkers.

Measuring sleep regularity: Theoretical properties and practical usage of existing metrics

STUDY OBJECTIVES

Sleep regularity predicts many health-related outcomes. Currently, however, there is no systematic approach to measuring sleep regularity. Traditionally, metrics have assessed deviations in sleep patterns from an individual's average. Traditional metrics include intra-individual standard deviation (StDev), Interdaily Stability (IS), and Social Jet Lag (SJL). Two metrics were recently proposed that instead measure variability between consecutive days: Composite Phase Deviation (CPD) and Sleep Regularity Index (SRI). Using large-scale simulations, we investigated the theoretical properties of these five metrics.

METHODS

Multiple sleep-wake patterns were systematically simulated, including variability in daily sleep timing and/or duration. Average estimates and 95% confidence intervals were calculated for six scenarios that affect measurement of sleep regularity: 'scrambling' the order of days; daily vs. weekly variation; naps; awakenings; 'all-nighters'; and length of study.

RESULTS

SJL measured weekly but not daily changes. Scrambling did not affect StDev or IS, but did affect CPD and SRI; these metrics, therefore, measure sleep regularity on multi-day and day-to-day timescales, respectively. StDev and CPD did not capture sleep fragmentation. IS and SRI behaved similarly in response to naps and awakenings but differed markedly for all-nighters. StDev and IS required over a week of sleep-wake data for unbiased estimates, whereas CPD and SRI required larger sample sizes to detect group differences.

CONCLUSIONS

Deciding which sleep regularity metric is most appropriate for a given study depends on a combination of the type of data gathered, the study length and sample size, and which aspects of sleep regularity are most pertinent to the research question.

Shift work disorder and related influential factors among shift workers in China

BACKGROUND

Shift work may cause insomnia and sleepiness in individuals. The present study aimed to exam shift work disorder (SWD), and to investigate their associations with individual characteristics.

METHODS

A total of 1833 shift workers were assessed using the Pittsburg Sleep Quality Index, Epworth Sleepiness Scale (ESS), Composite Scale of Morningness (CSM), Circadian Type Inventory (CTI), Center for Epidemiologic Studies-Depression Scale (CES-D), Beck Anxiety Inventory (BAI) and other self-compiled socio-demographic questionnaires.

RESULTS

In the current sample, 17.1% shift workers have experienced insomnia symptoms, 20.9% were tested for daytime sleepiness, and 19.9% were categorized as having SWD. Logistics regressions revealed that history of mental disorders (OR = 2.04, 95% CI = 1.30-3.21), chronic physical illness (OR = 1.53, 95% CI = 1.17-1.99), CES-D scores (OR = 1.03, 95% CI = 1.02-1.05), BAI scores (OR = 1.04, 95% CI = 1.03-1.06), languid/vigorous tendencies (OR = 1.06, 95% CI = 1.03-1.10) were positively associated with the onset of SWD, while morningness (OR = 0.97, 95% CI = 0.94-0.99) decreased the odds of SWD onset.

CONCLUSIONS

These findings suggested that attention should be drawn to individuals with mental and chronic diseases in when scheduling work shifts. While SWD and its associates should be considered when providing psychological services to shift workers.

Hilaire MA, O’Brien CS, Stone KL, Phillips AJ, Klerman EB, Qadri S, Wright KP, Halbower AC, Segar JL, McGuire JK, Vitiello MV, de la Iglesia HO, Poynter SE, Yu PL, Sanderson AL, Zee PC, Landrigan CP, Czeisler CA, Lockley SW. Extended Work Shifts and Neurobehavioral Performance in Resident-Physicians

OBJECTIVES

Extended-duration work rosters (EDWRs) with shifts of 24+ hours impair performance compared with rapid cycling work rosters (RCWRs) that limit shifts to 16 hours in postgraduate year (PGY) 1 resident-physicians. We examined the impact of a RCWR on PGY 2 and PGY 3 resident-physicians.

METHODS

Data from 294 resident-physicians were analyzed from a multicenter clinical trial of 6 US PICUs. Resident-physicians worked 4-week EDWRs with shifts of 24+ hours every third or fourth shift, or an RCWR in which most shifts were ≤16 consecutive hours. Participants completed a daily sleep and work log and the 10-minute Psychomotor Vigilance Task and Karolinska Sleepiness Scale 2 to 5 times per shift approximately once per week as operational demands allowed.

RESULTS

Overall, the mean (± SE) number of attentional failures was significantly higher (P =.01) on the EDWR (6.8 ± 1.0) compared with RCWR (2.9 ± 0.7). Reaction time and subjective alertness were also significantly higher, by ∼18% and ∼9%, respectively (both P <.0001). These differences were sustained across the 4-week rotation. Moreover, attentional failures were associated with resident-physician-related serious medical errors (SMEs) (P =.04). Although a higher rate of SMEs was observed under the RCWR, after adjusting for workload, RCWR had a protective effect on the rate of SMEs (rate ratio 0.48 [95% confidence interval: 0.30-0.77]).

CONCLUSIONS

Performance impairment due to EDWR is improved by limiting shift duration. These data and their correlation with SME rates highlight the impairment of neurobehavioral performance due to extended-duration shifts and have important implications for patient safety.

Health Risks and Potential Predictors of Fatigue and Sleepiness in Airline Cabin Crew

Background: Aviation pilots and cabin crew regularly undertake shift work, and may experience circadian disruption, restricted sleep, sleepiness and impaired health. Research on aviation fatigue and sleepiness has focused on pilots, with less being known about cabin crew. This study aimed to identify likely predictors of fatigue, sleepiness, shift work disorder (SWD) and depression in cabin crew. Methods: An online anonymous survey was distributed to active cabin crew around the world. It measured sleepiness, fatigue, and screened for insomnia, depression and SWD. Information on individuals’ habits and work schedules were collected. Results: 930 valid responses were analysed. 63.5% of the sample had abnormal levels of fatigue and 46.9% experienced excessive daytime sleepiness. 68.0% were at risk for SWD, 57.7% screened positive for insomnia, and 40.0% for depression. Caffeine and use of alcohol and drugs for sleep were independently associated with insomnia and SWD (p < 0.05), whereas, type of route (international, domestic, both) and number of duty days per week predicted fatigue (p < 0.05). Conclusions: Cabin crew had a high prevalence of fatigue, sleepiness and elevated risk for SWD, insomnia and depression. Many cabin crew engaged in behaviours detrimental to good sleep hygiene, highlighting targets for future interventional studies.

Pediatric Resident Engagement With an Online Critical Care Curriculum During the Intensive Care Rotation

OBJECTIVES

Residents are often assigned online learning materials as part of blended learning models, superimposed on other patient care and learning demands. Data that describe the time patterns of when residents interact with online learning materials during the ICU rotation are lacking. We describe resident engagement with assigned online curricula related to time of day and ICU clinical schedules, using website activity data.

DESIGN

Prospective cohort study examining curriculum completion data and cross-referencing timestamps for pre- and posttest attempts with resident schedules to determine the hours that they accessed the curriculum and whether or not they were scheduled for clinical duty. Residents at each site were cohorted based on two differing clinical schedules-extended duration (>24 hr) versus shorter (maximum 16 hr) shifts.

SETTING

Two large academic children's hospitals.

SUBJECTS

Pediatric residents rotating in the PICU from July 2013 to June 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred and fifty-seven pediatric residents participated in the study. The majority of residents (106/157; 68%) completed the curriculum, with no statistically significant association between overall curriculum completion and schedule cohort at either site. Residents made more test attempts at nighttime between 6 PM and 6 AM (1,824/2,828; 64%) regardless of whether they were scheduled for clinical duty. Approximately two thirds of test attempts (1,785/2,828; 63%) occurred when residents were not scheduled to work, regardless of time of day. Forty-two percent of all test attempts (1,199/2,828) occurred between 6 PM and 6 AM while off-duty, with 12% (342/2,828) occurring between midnight and 6 AM.

CONCLUSIONS

Residents rotating in the ICU completed online learning materials mainly during nighttime and off-duty hours, including usage between midnight and 6 AM while off-duty. Increasing nighttime and off-duty workload may have implications for educational design and trainee wellness, particularly during busy, acute clinical rotations, and warrants further examination.

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

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.).