IS THERE AN OPTIMUM NUMBER OF NIGHT SHIFTS - RELATIONSHIP BETWEEN SLEEP, HEALTH AND WELL-BEING

By concentrating on the impact of a specific shift-system feature on t he well-being of those concerned, rather than on the impact of the shi ft system as a whole, one might be able to offer more meaningful sugge stions as to what constitutes a better form of shift system. The prese nt study focused on the impact of the number of consecutive night shif ts worked on the health and well-being of two groups of nurses (perman ent night and rotating shift). All nurses completed a copy of the Stan dard Shiftwork Index, which is a set of questionnaires designed for co mparing the effects of different types of shift system on large groups of workers. it includes measurements of psychological ill-health, phy sical ill-health, chronic fatigue, social and domestic disruption, att itudes cowards shiftwork, sleep quality and sleep habits. Results show ed clearly the impact of the number of consecutive nights worked on he alth and well-being, nor directly, but indirectly through the impact o n sleep duration and sleep quality. Sleep duration was shown to increa se with more consecutive nights worked. This in turn was found to pred ict sleep quality, which in turn was found to be the stronger direct p redictor of psychological and physical ill-health: i.e. better health was associated with longer and better quality sleeps. Explanations in terms of circadian adaptation are discussed.