Part 1 of 2


Too exhausted to act safely?

How to assess worker fatigue

By Patrice Spath, RHIT
Brown-Spath & Associates
Forest Grove, OR

Concerns about the relationship between worker fatigue and patient safety are a relatively new issue for the health care industry. Residents are now limited to working 80 hours a week, and various groups have recommended that nurses should not provide direct patient care for more than 12 hours in any given 24-hour period or in excess of 60 hours in any seven-day period. Limiting worked hours can reduce caregiver fatigue; however, even people working 40 or less hours a week can make fatigue-related errors. When a significant adverse patient incident occurs, it is not sufficient to merely examine the worked hours of those involved to determine the potential for worker fatigue. It is true that long hours or overtime assignments may cause staff to be working at a less than fully alert state. However sleepiness on the job can be caused by a variety of factors, not just worked hours. Described below are techniques for examining whether worker fatigue-states contributed to an adverse patient incident.

Because physicians and staff members must work long and unusual hours to meet the needs of patients, fatigue should always be considered as a potential underlying factor in any significant adverse event. During investigation of the event a systematic evaluation of all factors affecting worker fatigue should be undertaken. There are many manifestations of human error, some due to fatigue or reduced alertness. If fatigue is found to be a root cause of the incident, the next step will be to correct the situation. To identify fatigue-related concerns, start by evaluating the following four factors:

  1. Time of day of the occurrence. If the incident occurred between 3 and 5 p.m. or between 3 and 5 a.m., fatigue may have played a role.
  2. Disruption of people’s normal circadian rhythm. If those directly involved in the incident were working at a time when they normally would have been sleeping, fatigue may have played a role.
  3. Number of hours since people last slept. If the involved individuals had been awake for more than 16 hours when the event occurred, fatigue may have played a role.
  4. The 72-hour sleep history of people directly involved in the incident. If those directly involved had been averaging less than seven hours of sleep per night, fatigue may have played a role.

If this initial inquiry indicates a problem, then fatigue should be investigated in greater detail. Use a two-stage process for this investigation. First, establish that the person or persons involved in the incident were in a fatigued state, and second, determine if the unsafe act or decision was consistent with the type of behavior expected of a fatigued person.

To ascertain whether people involved in the incident were in a fatigued state, you need to know more about what created this situation. This requires an in-depth look into significant factors relating to fatigue. Probing questions should be asked about sleep quantity and quality prior to the incident, work history, and work schedules. To establish whether the people involved were sleep deprived at the time of the incident, ask questions such as:

  • What was the length of your last consolidated sleep period? (Ideal: seven to nine hours.)
  • When did your last consolidation sleep period start? (Ideal: normal circadian rhythm, late evening.)
  • Was your sleep period interrupted? If so, for how long (Ideal: no interruptions.)
  • The quality of a person’s sleep can also contribute to a fatigued-state. To examine sleep quality, consider:
  • How did the individual’s sleep period immediately prior to the incident relate to his/her normal sleep cycle (usual start/stop time)?
  • How many times was the individual awakened during his/her last sleep period?
  • Was the individual’s environment conducive to restorative sleep (e.g. quiet, dark room, own bed)?
  • Does the individual have any sleep pathologies (e.g. insomnia, sleep apnea)?

Factors attributed to the work history of involved individuals also can create fatigue states. Establish whether the hours worked and the type of duty or activities involved had an impact on the person’s quantity or quality of sleep. For examine, consider:

  • How many hours was the individual on duty and/or call prior to the incident?
  • What was the individual’s work history in the preceding week?
  • Did the individual have adequate rest breaks (e.g. regularly scheduled 10- to 15-minute complete breaks from work)?

Work schedule irregularity can cause worker fatigue-states that result in an adverse patient incident. To determine whether scheduling was problematic with regard to its impact on an individual’s sleep quantity or quality, ask questions such as:

  • Was the individual working an evening or night shift? If yes, is this the individual’s permanent shift or do they rotate between shifts?
  • Was the individual working overtime or scheduled for a double shift?
  • Was the individual expected to perform critical tasks at a time when he or she was least likely to be alert (within the context of the person’s usual circadian rhythm)?

If worker fatigue is established as a possible root cause of the adverse event, next look at the link between fatigue and the unsafe act or decision. What you want to determine is whether or not a cause-and-effect relationship exists. Several performance impairments can be directly attributed to individual fatigue. Listed in Figure 1 are common fatigue-related performance impairments and how these impairments may be manifested.

If the adverse event investigation team substantiates worker fatigue as one of the root causes of the incident, actions should be taken to improve the alertness of caregivers. Researchers have found that a complex interaction of timing of sleep, work schedule, environment, and personal habits all affect worker fatigue. Mitigating the effects of these issues will require a spectrum of approaches. Techniques for reducing staff member fatigue and the patient safety risks that it carries are discussed in part 2 of this series.