Dados do Trabalho

Título

Title: Effects of chronotype on sleep duration and psychomotor performance throughout a complete shift rotation schedule: a prospective study in a real-life condition

Introdução

Recent evidence demonstrates that shift work is associated to negative effects on psychomotor performance, which include cognitive impairments such as attention drop. One of the main triggers for such impairments seems to be deterioration of the sleep pattern. Individual worker characteristics - such as the chronotype – could also be associated with psychomotor performance

Objetivo

To evaluate the effect of chronotype on the sleep duration and psychomotor performance in industrial workers throughout a complete shift rotation schedule.

Métodos

Thirty shift workers participated in this observational and prospective study. Sociodemographic characteristics, health behaviors and Munich Chronotype Questionnaire –(MCTQ) were collected. Individuals were followed for all seven consecutive days carried out as follow: two days (D1 and D2) working during the day (08:00- 16:00); two days (D3 and D4) working during the evening (16:00 – 00:00); two days (D6 and D7) working during the night (00:00 – 08:00). Evaluations regarding the work performance by Psychomotor Vigilance Test (PVT) and sleep by actigraphy were assessed over the seven days. The Generalized Linear Models (GLM) were used to analyze the effect of chronotype, shift rotation and its interaction on sleep duration and psychomotor performance variables.

Resultados

Intermediate (I-type) and late types (L-type) – but not evening types (E-type) - had a longer sleep duration in day work than night work (I-type: 08:17:16 ± 0:20:45 and 05:29:38 ± 0:37:36, respectively; L-Type: 08:10:52 ± 0:21:06 and 4:30:49 ± 0:35:17, respectively; p <0.001 for all).
We found that L-type had a higher number of lapses of attention during day work (06.18 ± 2.68) than E-type and I-type (1.0 ± 0.63 and 1.67 ± 0.59, respectively; p<0.001). During evening work, the I-type had a lower number of lapses of attention (0.87 ± 0.22) than E-type and L-type (3.44 ± 0.73, 6.31 ± 1.98, respectively; p <0.001). For the night work, the L-type had a higher number of lapses of attention (4.06 ± 1.18) than I-type (1.50 ± 1.98, p <0.001).

Conclusões

Late chronotype workers presented a greater mean of lapses of attention in all shifts of the schedule, while the E-type group increased the number of lapses of attention from morning to evening and night shift. Intermediate chronotypes oscillated less in the number of attention lapses

Palavras-chave

Chronotype. Sleep duration. Psychomotor performance. Shift rotation schedule