LAUSR

BACKGROUND Obstetrics and gynecology requires complex decision-making and skills due to unexpected high-risk situations. These skills are influenced by alertness, reaction time and concentration. Night shifts result in sleep deprivation, which might impair these functions, although it is still unclear to what extent. OBJECTIVE The aim of this study was to investigate whether a night shift routinely impairs the Obstetrics or Gynecology consultants' and residents' fitness to perform (FTOP) and whether this reaches a critical limit as compared to relevant frames of reference. STUDY DESIGN Residents (n=33) and consultants (n=46) in obstetrics and gynecology conducted multiple measurements at precall, postcall and non-call moments with the FTOP self-test. The self-test consists of a s-eye coordination task that is able to objectively measure alertness, reaction time, concentration and hand-eye coordination, and visual analogue scales to subjectively score alertness. The test is validated with a socio-legal reference of a 0.06% ethanol blood concentration (the peak level after two units of alcohol, legal driving limit). This equals -1.37% on the objective score and -8.17 points on subjective alertness. Linear Mixed Models were used to analyse the difference within subjects over a night shift, integrating repeated measures over time. RESULTS The overnight objective difference between postcall and precall measurements was -0.62 (p<0.05) for residents and 0.28 (p=NS) for consultants, both not exceeding the socio-legal reference as a group. Objective impairment exceeded the reference for 31% of the residents and 28% of the consultants. Subjective alertness decreased in residents (-18.26, p<0.001) and consultants (-10.85, p<0.001), both exceeding the reference. No residents had to continue work postcall versus 7.8% of the consultants. None of the consultants that had to continue work were in an objective critically impaired state. CONCLUSION This study provides insight and awareness of individual performance after night shifts with clear frames of reference. Performance of residents is negatively and significantly affected by night shifts, therefore a scheduled day off postcall is justified. Consultants showed no overall impairment, however a quarter did exceed the alcohol limit reference after their night shift. If not logistically feasible to schedule a protected day off after a night shift, our group recommends safe shift scheduling, including options to transfer care after a demanding night shift to prevent working in a compromised state.