Sleep and Health in Shift Working Nurses

In this thesis, the prevalence of Shift Work Disorder (SWD) in a sample of nurses, and the association between SWD and work characteristics, health outcome and personality (paper 1) have been investigated. Next, the psychometric properties of the “Bergen Shift Work Sleep Questionnaire” (BSWSQ) were evaluated (paper 2). The BSWSQ evaluates sleep and sleepiness problems in relation to day shifts, evening shifts, night shifts and rest-days. The validated BSWSQ was used to investigate how different work shifts and work schedules affected problems with sleep and sleepiness (paper 3). In paper 1, three symptom-based questions were used to assess the prevalence of symptoms indicative of SWD. To evaluate the accuracy of these questions, two additional measurement procedures were used for comparison. All three procedures were based on the International Classification of Sleep Disorders, second edition (ICSD-2) diagnostic criteria that entail the presence of a sleep or sleepiness problem associated with a work schedule that imposes wakefulness during the usual time for sleep (American Academy of Sleep Medicine (AASM), 2005). Logistic regression analyses were performed with symptoms indicative of SWD as outcome variables. Nurses (n = 1968) reported their age, gender, type of work schedule, commute duration, fraction of a full-time position, presence of children in household (yes/no), number of nights and number of shifts separated by less than 11 hours worked during the previous year, use of sleep medication, melatonin and bright light therapy. All of the nurses completed the Bergen Insomnia Scale, the Epworth Sleepiness Scale, the Global Sleep Assessment Questionnaire, the Diurnal Scale, the Revised Circadian Type Inventory, the Dispositional Resilience (Hardiness) Scale – Revised, the Fatigue Questionnaire, questions about alcohol and caffeine consumption, as well as the Hospital Anxiety and Depression Scale.