Objectives This discussion paper aims to provide scientifically based recommendations on night shift schedules, including consecutive shifts, shift intervals and duration of shifts, which may reduce health and safety risks. Short-term physiological effects in terms of circadian disruption, inadequate sleep duration and quality, and fatigue were considered as possible links between night shift work and selected health and safety risks, namely, cancer, cardio-metabolic disease, injuries, and pregnancy-related outcomes.

Method In early 2020, 15 experienced shift work researchers participated in a workshop where they identified relevant scientific literature within their main research area.

Results Knowledge gaps and possible recommendations were discussed based on the current evidence. The consensus was that
schedules which reduce circadian disruption may reduce cancer risk, particularly for breast cancer, and schedules that optimize sleep and reduce fatigue may reduce the occurrence of injuries. This is generally achieved with fewer consecutive night shifts, sufficient shift intervals, and shorter night shift duration.

Conclusions Based on the limited, existing literature, we recommend that in order to reduce the risk of injuries and possibly breast cancer, night shift schedules have: (i) ≤3 consecutive night shifts; (ii) shift intervals of ≥11 hours; and (iii) ≤9 hours shift duration. In special cases – eg, oil rigs and other isolated workplaces with better possibilities to adapt to daytime sleep – additional or other recommendations may apply. Finally, to reduce risk of miscarriage, pregnant women should not work more than one night shift in a week.

This article refers to the following texts of the Journal: 2013;39(4):325-334  2018;44(4):394-402  2018;44(4):403-413  2018;44(4):385-393  2019;45(3):256-266  2019;45(2):166-173  2020;46(4):446-453  2020;46(6):570-578  2020;46(6):645-649  2010;36(2):121-133  2015;41(3):268-279  2012;38(4):380-390

The following articles refer to this text: 2020;46(6):554-556; 2021;47(6):446-455; 0;0 Special issue:0

Key terms cancer; cardio-metabolic disease; circadian disruption; health; injury; night shift; night shift work; night work; pregnancy; risk; safety; schedule; shift work; shift work schedule; shift worker; sleep duration; sleep quality; sleepiness

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