Sleep and Fatigue in Nurses in Relation to Shift Work

Abstract

Introduction: Sufficient and good quality sleep is crucial for shift workers because of its implications for alertness, recovery and health. The aim of the study was to follow the effects of night shifts and overtime work on sleep and fatigue of hospital nurses in Bulgaria. Methods: The study is cross-sectional and comprised 1340 nurses of age 50.1 ± 10.1 years from Sofia hospitals. Anonymous questionnaire survey included Karolinska Sleep Diary, demographic information, work place variables, working hours and shift system. The statistical analyses were carried out with SPSS. Results: 27.4% of the nurses worked only day shifts, but part of them were with history of night shifts. 18.9% worked from 1 to 4 night shifts, and 46.7% more than 5 night shifts. Great deal of the nurses worked more than 40 h weekly as follows: 34.2% worked 41–50 h per week, 16.8% - 51–60 h and 10.6% >61 h. The reported sleep duration did not differ between the groups of nurses working day shifts and different number of night shifts or with the number of work hours weekly. The quality of sleep, estimated by SQI was worse with the increase of number of night shifts and in comparison to nurses working only day shifts (F = 6.877, p = 0.000) and with increase of the hours worked weekly (F = 5.085, p = 0.002). With the increase of the number of night shifts and the working hours weekly the insufficiency of sleep, fatigue in the morning after awakening and sleep throughout increased highly significantly. Discussion: Shift working with more night shifts monthly and overtime hours weekly contributed to impaired sleep in the studied group of nurses. The sleep impairment was more evident within the increase in the number of night shifts.