Guidelines for the medical surveillance of shift workers.

Occupational health physicians should evaluate workers' fitness for shift and night work before their assignment, at regular intervals, and in cases of health problems connected with night work. The evaluation should be accompanied by a careful job analysis to ensure that shift schedules are arranged according to ergonomic criteria. This arrangement can reduce health problems and make coping with irregular workhours possible, even for people suffering from contraindicative illnesses. Both health disorders representing absolute or relative contraindication and actual work conditions should be taken into account. Health checks should be aimed at detecting early signs of intolerance, such as sleeping and digestive trouble, drug consumption, accidents, and reproductive function. Their periodicity should be set in relation to specific work conditions, individual characteristics, and social factors known to influence tolerance to shift work. Shift workers should receive clear information on the possible negative effect of shift work, and also counseling for coping with shift and night work.