Efeito da rotação dos turnos de trabalho sobre o desempenho psicomotor: um estudo prospectivo e observacional sob condições de vida real

Abstract

Background: The effect of shift work rotation on psychomotor perfomance and its interaction with variables known to impair alertness - such as circadian misalignment, overweight and obesity, and individual chronotype - has been little explored in the literature. Objectives: We aimed to evaluate the influence of shift work rotation on psychomotor performance throughout a complete shift rotation schedule. Methods: The study was conducted with 30 males working rotating shifts from a mining company under real life conditions. Individuals were evaluated over seven days in a shift schedule carried out as follow: two days of day work (D1 e D2), two days of evening work (D3 e D4), 24-hour free day and two days of night work (D6 e D7). Work performance was evaluated by psychomotor vigilance task (PVT), and actigraphy was used to measure the stability and fragmentation of rest-activity rhythm based on intradaily variability (IV) and interdaily stability (IS) and to determine sleep duration. The chronotype was determine using Munich Chronotype Questionnaire adapted for shift workers (MCTQshift). Results: We found a significant effect of the shift, body mass index (BMI), IS and IV on lapses in attention. More lapses occurred on D7 than D1, D2, D3 and D4 of the schedule shift. The obese group presented a higher number of lapses in attention than eutrophic. The interaction between day and IS showed that less synchronized individuals presented a higher number of lapses in attention on D7 than D1 and, for the interaction between day and IV, more fragmented individuals presented a higher number of lapses in attention on D7 than D6. We found a significant effect of the interaction between chronotype and work schedules on mean of reaction time (MRT) in pre-and post work and number of lapses of attention (p<0.001). In general, early types showed higher values of MRT-pre and post work, while late-type workers presented a greater number of lapses of attention along the advancement of the schedule. Intermediate-types were the least impaired in terms of psychomotor performance. Conclusion: We conclude that higher BMI, lower synchronization and higher fragmentation of the rest-activity pattern and chronotype influenced lapses in attention throughout the shift rotation. In addiction, we conclude that higher values of BMI, less synchronization and greater fragmentation of the RAR influenced the attention lapses throughout the shift rotation. In terms of psychomotor performance, the intermediate chronotype seems to be the best to work on rotation schedule. Keywords: Shift rotation. Psychomotor performance. Misalignment circadian. Chronotype.