Fatigue and the Shiftworker: Firefighters Working on a Rotating Shift Schedule

Abstract

Fatigue has often been viewed as a simple variable that is positively correlated with time on task in the workplace and is produced mainly by physical activity. However, shiftwork researchers have demonstrated time-of-day differences for variables including sleepiness and mood, thereby challenging this notion of fatigue. Using a within-subjects design, the present study advances this research by searching for differences in time-of-day interactions in firefighters' sleep length, sleepiness, and mood ratings as a function of shift. We examined reductions in sleep length associated with shiftwork and used sleepiness and mood scales to assess the effects of these reductions. Participants completed surveys throughout a complete cycle of their shift schedule. The study showed that firefighters working on a rotating 8-h shift schedule will sleep less and will report lower positive mood scores, higher negative mood scores, and greater sleepiness ratings on the night shift. Additionally, it was shown that over the course of a shift (two weeks), firefighters were unable to adapt to changes in their sleep schedule. Finally, the significant interactions that were observed challenge the historical, singular notion of fatigue.

Mnemonic Processing in Air Traffic Controllers: Effects of Task Parameters and Work Organization

“…Second, air traffic control activities differ between day and night, as high traffic during the daytime involves sustained periods of high task requirements and attentional demands, whereas low traffic during the night would favor boredom and sleepiness (Costa, 1999;Lille & Cheliout, 1982;Luna et al, 1997;Straussberger, Kallus, & Schäfer, 2006). Third, shift work itself has disruptive effects, particularly on sleep that is normally required to maintain alertness, concentration, and performance (Dinges et al, 1997;Glazner, 1991;Paley & Tepas, 1994), thereby aggravating the noctur- nal decline in cognitive behavior (Akerstedt et al, 2004;Costa, 1999;Dinges et al, 1997;Folkard & Tucker, 2003;Tucker et al, 1996). In this study, the shift system took advantage of shift-scheduling features shown to reduce the disruptive effects of shift work, such as direction of rotation, number of night shifts, and time off between shifts (for a review, see Della Rocco & Nesthus, 2005).…”

Risk of health complaints and disabilities among Dutch firefighters

“…It did not, in fact, confirm that firefighters had a higher risk of developing hypertension, heart, fatigue, stomach or sleep complaints related to working 24-h shifts (Å akerstedt 1990;Bøggild and Knutsson 1999;Fischer et al 2001;Gilberg 1998;Harma 1995;Morikowa et al 1999;Paley and Tepas 2002;Peter et al 1999). Other studies report an association between shift work and hypertension (OR=2.2-4.0) (Morikowa et al 1999;Peter et al 1999) and heart complaints (e.g.…”

“…Musculoskeletal complaints (Reichelt and Conrad 1995), cardiovascular disorders (Melius 1995) and fatigue and sleep complaints (Paley and Tepas 2002) have been reported among firefighters. These complaints may restrict firefighters during actual performance of firefighting tasks and activities (Matticks et al 1992).…”

A Survey of Fatigue in Selected United States Air Force Shift Worker Populations

“…The problem with this approach is that it assumes fatigue is highly and positively correlated with time on task in the workplace. However, field research with shift workers as well as laboratory research has consistently demonstrated time-of-day differences in sleep, sleepiness, mood, and performance, indicating that all hours of the day are not equal and interchangeable (Caldwell & Gilreath, 2002;Monk, 1994;National Transportation Safety Board, 1999;Paley & Tepas, 1994). This point was reinforced in a study of shift working UAS crewmembers which found no association between reported fatigue levels and flying time histories (Tvaryanas et al, 2006).…”