SPEED AND DIRECTION OF SHIFT ROTATION

This review paper deals with the issue of shift rotation, i.e. the num ber of consecutive shifts of the same type and the order of change bet ween shifts. To minimize the disturbances of the circadian system and the accumulation of sleep deficits, rapidly and clockwise-rotating shi ft systems would seem to be preferable. Regarding consecutive night sh ifts, a week of night shifts seems to be the worst system with regard to performance and accidents. There is a lack of reliable data on the effects of permanent vs. rotating-shift systems on alertness, performa nce and accidents. This is also true for the comparison of forward (de laying) and backward (advancing) rotating-shift systems, although the former would seem to be associated with fewer problems. For both syste ms, controlled longitudinal studies are necessary.