[The influence of lifestyle and night-shift work on sleep problems among female hospital nurses in Japan]

In this study, by conducting a questionnaire survey, we aimed to clarify the situation regarding sleep disorders in female hospital nurses and their relation with night-shift work and lifestyle.

The subjects were female nurses working at 5 hospitals, each with more than 400 beds. The survey was carried out in July 2000. The questionnaire contained six items concerning sleep quality from the Pittsburgh Sleep Quality Index (PSQI), two new items on sleep drafted by ourselves, and some questions on lifestyle and shift-work status.

Among all female nurses, statistically significant differences were observed between those working and those not working night shifts for 7 items regarding sleep (P < 0.05). Significant correlations were observed between sleep disorders and the following factors: (1) working night shift, (2) having anxiety or stress, (3) getting less than 6 hours of sleep, (4) working in cities, (5) having children, and (6) bathing more than 1 hour before going to bed. In addition, significant correlations were observed between getting less than 6 hours of sleep and the following factors: (1) being 40 years of age or older, (2) working in cities, and (3) having anxiety or stress.

The results of this study suggest that sleep problems among nurses are associated not only with night-shift work but also with lifestyle. They also suggest that nurses who work night shifts, especially in Tokyo, should try to get sufficient hours of sleep to ensure good quality of sleep.