Research Article: Does work-induced fatigue accumulate across three compressed 12 hour shifts in hospital nurses and aides?

Date Published: February 7, 2019

Publisher: Public Library of Science

Author(s): Brennan J. Thompson, Rosemary Frey.


Fatigue-related impairments in the nursing workforce contribute to a multitude of health, safety, and economic consequences at the individual, organizational and societal levels. Long and compressed work schedules are commonly worked in the healthcare industry, but more research is needed to understand the cumulative effects of multiple work shifts on physiology-based performance outcomes in nurses. The purpose of this study was to compare the effects of a single nursing work shift versus three compressed (one every 24 hours) 12 hour shifts on performance-based fatigue in nurses and aides. Twenty-six fulltime hospital working nurses and aides (age = 36.1 ± 13.3 years) reported to the lab for testing before, immediately after working a single 12 hour shift, and after working three 12 hour shifts in a 72 hour period. Outcome measures included vigilance-based reaction time, lapses of attention, and muscle function assessments (lower and upper body muscle strength, explosive strength and vertical jump performance). All variables except hand grip strength showed a significant decline following the three work shifts. The psychomotor vigilance reaction time and lapses of attention variables also generally showed a significant decline from the end of shift one to the end of shift three, indicting an accumulation of fatigue in these metrics with increasing number of shifts worked. Muscle function variables responded early in the duty cycle, showing a significant decline after a single work shift, but did no further decline by the end of the third shift. These findings use objective measures to substantiate that fatigue impairments occur from working a single 12 hour shift, and in several instances, increase further with more successive work shifts. Caution should be employed by personnel and administrators with work schedules involving multiple compressed 12 hour shifts. Fatigue management strategies may be used to improve risks and consequences from fatigue-related mishaps, and this study reports several variables that appear sensitive to identifying and tracking fatigue in this population.

Partial Text

The evidence regarding the prevalence and consequences of fatigue in the at-risk nursing population has resulted in an urgency for increased awareness and effective management plans. Recently, many respected professional organizations have put forward position statements and guidelines drawing awareness to healthcare worker fatigue and its consequences [1–5], with the overall aim of these organizations to legitimize fatigue as a serious and pressing issue. For instance, the American Nurses Association [6] clarified that nurses have an “ethical responsibility and duty to their patients to recognize their level of fatigue before accepting patient assignments.”

All participants had been working in their current job (hospital, floor, shift type) for at least 3 months prior to the study, and the mean time at their current job for all participants was 3.4 years. The study sample was comprised of 16 RNs, 8 CNAs, and 2 LPNs, and the mean ± SD total hours worked over the three shifts was 37.5 ± 1.7 hours (range of 34–41.5 hours). During the three day work schedule, all participants worked at least 11.5 hours and not more than 14 hours for each work shift completed in the study.

The present investigation showed that fatigue-based impairments in various performance tasks were observed after a single 12 hour work shift, and that for some tasks, these impairments were more exacerbated following multiple (three successive) work shifts.

The demands of three consecutive (day-to-day) 12 hour nursing work shifts led to impairments in reaction time, greater lapses of attention reductions in multiple measures of muscle function. A particular novel finding was that vigilance-based reaction time measures showed an accumulating impairment progressively worsening from a single 12 hour shift to the end of the third shift. Several muscle function assessments also showed sensitivity to nursing work fatigue, and these were impaired early on in the work cycle such that they were significantly reduced after only a single 12 hour shift. This study provides a basis for describing fatigue characteristics in nursing workers across multiple shifts, however, future studies should build from this work and include longer work shift and, if possible, more fatigue assessment time points to help determine when fatigue accumulation becomes the most severe, and at what point recovery strategies may most effectively be applied across a nurses work schedule in order to reduce the heavy risks and burdens associated with fatigue-induced impairments in performance. These findings demonstrate that fatigue is objectively substantiated in nurses working 12 hour shifts. Thus, nursing staff, managers, and administrators may consider using fatigue management strategies as a countermeasure to the safety consequences associated with nurse fatigue. In particular, our work in this area provides support for the use of the computer based PVT as a useful and sensitive test for identifying/tracking fatigue in this specific population, and further work could develop more mobile muscle function assessments in order to improve the feasibility of using the rate of torque development variable as another potentially useful indicator of impairments in lower body muscle function.




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