Night Shift Duty Research Articles

Brachial artery endothelial function in residents and fellows working night shifts

Brachial artery endothelial function, which is measured as responsiveness to reactive hyperemia (flow-mediated dilation [FMD]) was abnormal in residents and house staff after a 24-hour shift, including night duty. The greatest decrease in FMD was observed in physicians with a longer history of night-shift duty and in those reporting fewer sleeping hours during the shift. The finding that FMD is decreased after night duty raises the issue of the effects of shift duty on cardiovascular function in healthcare personnel, particularly in those undertaking night duty for a prolonged period of time.

Risk factors for physical assault: State-managed workers’ compensation experience

Background The estimation of incidence and evaluation of risk factors associated with nonfatal occupational assault injuries have rarely been documented in a statewide population context. A state-managed workers’ compensation system can provide estimates of incidence of such injuries and allow evaluation of risk factors. Methods Using claims data from the state-managed West Virginia Workers’ Compensation, the incidence rates of workplace injuries resulting from physical assault were estimated for the period 1997–1999. Data on potential risk factors were obtained from the claim-related electronic data files, and the risk associated with each factor was assessed using proportional injury ratios (PIRs). Results During the study period, 2122 compensated injuries were associated with workplace violence. The incidence of assault injuries was 108.2 cases per 100,000 employee years. Women sustained a higher incidence than men. Healthcare workers, public safety workers, and teachers accounted for almost 75% of all assault injuries. Workers in these occupations also differed from each other with regard to seasonality and timing of assault, perpetrator–victim relationship, and types of injury. Evidence of gender–occupation interaction indicated higher risk of assault injury in men compared to women across the three leading occupations. Nighttime work shifts were associated with greater risk of assault for female healthcare workers (PIR=1.8; 95% confidence interval, 1.09–2.87). Conclusion The healthcare sector sustained the bulk of assault injuries in West Virginia. Although the majority of healthcare-sector employees were women, the risk of assault injuries was higher in male employees. Risk factors and injury characteristics identified in this study, particularly for three high-risk occupations, should help develop strategies for preventing workplace violence. Protecting female healthcare workers on night-shift duty, especially in nursing home settings, appears to be an important target for intervention.

Randomized Clinical Trial of Melatonin After Night-Shift Work: Efficacy and Neuropsychologic Effects

Objective: Melatonin has received considerable publicity for its sleep-promoting properties; however, there is little scientific evidence of its efficacy. The objective of this study is to determine whether there are measurable beneficial effects from exogenous melatonin in emergency physicians after intermittent night-shift duty. Methods: This randomized, placebo-controlled, double-blind, crossover trial was conducted in the emergency department of an urban tertiary care hospital. Fifteen emergency physicians were given melatonin 5 mg or placebo for 3 consecutive nights after night-shift duty with crossover to the opposite agent after a subsequent block of night shifts. The primary outcome measure was the global assessment of recovery measured by a visual analog scale. Secondary outcome measures included sleep quality, duration, and tiredness. In addition, the Profile of Mood States questionnaire and neuropsychologic testing were performed. Results: There was no difference between melatonin and placebo in the global assessment of recovery (60.4±16.9 and 58.9±14.5, respectively; P =.29). There were no differences in sleep quality, duration or tiredness scores, sleep latency, hours of sleep obtained per night, and night or early awakening at any measurement point. Profile of Mood States and neuropsychologic test performances were similar. Conclusion: We found no beneficial effect of melatonin on sleep quality, tiredness, or cognitive function in emergency physicians after night-shift duty. Our results suggest that exogenous melatonin is of limited value in recovery from night-shift work in emergency physicians. [Wright SW, Lawrence LM, Wrenn KD, Haynes ML, Welch LW, Schlack HM: Randomized clinical trial of melatonin after night-shift work: Efficacy and neuropsychologic effects. Ann Emerg Med September 1998;32:334-340.]