Exploratory study of the effects of sex and hormonal contraceptives on alertness, fatigue, and sleepiness of police officers on rotating shifts.

Study objectives: This exploratory study assessed the impact of sex and hormonal contraceptives (HC) use on the homeostatic and diurnal variation of alertness, fatigue, sleepiness, psychomotor performance, and sleep behavior in police officers working rotating shifts.

Methods: A total of 56 men and 20 women (6 using, 11 not using, and 3 with unknown use of HC) participated in an observational study throughout a month-long work cycle. Participants wore an actigraph, filled out a sleep and work log, answered questionnaires (Samn-Perelli, KSS, Visual Analogue Scales), and completed 5-min Psychomotor Vigilance Tasks (PVT) according to an ecological momentary assessment approach. Linear mixed-effects models were used to analyze the effects of group (men, women, and HC use), time awake, and time of day on the dependent variables.

Results: Self-reported parameters and performance significantly varied with time awake and time of day. Women were more fatigued and sleepier than men, when considering both time awake and time of day. Compared to men, women using HC were more fatigued, less alert, and sleepier. Women had less attention lapses than men after 7 and 17 h awake, although no main effect of HC was detected.

Conclusions: Women tended to rate themselves as more fatigued than men, especially when using HC. Surprisingly, psychomotor performances of women were sometimes better than those of men. This exploratory study indicates that sex and HC are important factors to consider in occupational medicine.