Comparison of sleep disturbances in shift workers and people working with a fixed shift

Different types of sleep disturbances can have a serious negative effect on a person’s ability, function and overall well-being. One of the most important issues that can result in sleep disturbances are occupational causes, the most important among them is shift work. The objective of this study was to compare the prevalence of sleep disturbances between shift work and non shift workers. This study was designed as a case-control study in 196 shift workers and 204 non-shift workers in a textile factory. The data were collected by using a comprehensive questionnaire including Pittsburg Sleep Quality Index questionnaire, Berlin Questionnaire, Epworth Sleepiness Scale, Insomnia Severity Index and Restless Leg Syndrome Questionnaire. Data analyses were carried out using the SPSS software version 13 by student's t-test, Chi square and multiple logistic regressions. The duration of night sleep in shift workers was less than day workers (p<0.001). Prevalence of poor sleep quality and insomnia were higher in shift workers significantly than non shift workers (p<0.001, OR=2.3; 95% CI: 1.7-2.9). The most prevalent type of insomnia was problems in initiating sleep (P=0.022, OR=2.2; 95% CI: 1.5-3.2). There was no difference in the prevalence of excessive daytime sleepiness, restless leg syndrome, snoring, obstructive sleep apnea and different types of parasomnias between two groups. Reduced length of sleep and higher prevalence of poor sleep quality and insomnia in shift workers emphasizes the importance of serious attention to sleep disorders in shift workers.