Associations between night work and anxiety, depression, insomnia, sleepiness and fatigue in a sample of Norwegian nurses.
BACKGROUND
Night work has been reported to be associated with various mental disorders and complaints. We investigated relationships between night work and anxiety, depression, insomnia, sleepiness and fatigue among Norwegian nurses.


METHODS
The study design was cross-sectional, based on validated self-assessment questionnaires. A total of 5400 nurses were invited to participate in a health survey through the Norwegian Nurses' Organization, whereof 2059 agreed to participate (response rate 38.1%). Nurses completed a questionnaire containing items on demographic variables (gender, age, years of experience as a nurse, marital status and children living at home), work schedule, anxiety/depression (Hospital Anxiety and Depression Scale), insomnia (Bergen Insomnia Scale), sleepiness (Epworth Sleepiness Scale) and fatigue (Fatigue Questionnaire). They were also asked to report number of night shifts in the last 12 months (NNL). First, the parameters were compared between nurses i) never working nights, ii) currently working nights, and iii) previously working nights, using binary logistic regression analyses. Subsequently, a cumulative approach was used investigating associations between NNL with the continuous scores on the same dependent variables in hierarchical multiple regression analyses.


RESULTS
Nurses with current night work were more often categorized with insomnia (OR = 1.48, 95% CI = 1.10-1.99) and chronic fatigue (OR = 1.78, 95% CI = 1.02-3.11) than nurses with no night work experience. Previous night work experience was also associated with insomnia (OR = 1.45, 95% CI = 1.04-2.02). NNL was not associated with any parameters in the regression analyses.


CONCLUSIONS
Nurses with current or previous night work reported more insomnia than nurses without any night work experience, and current night work was also associated with chronic fatigue. Anxiety, depression and sleepiness were not associated with night work, and no cumulative effect of night shifts during the last 12 months was found on any parameters.
Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway. nicolas.oyane@gmail.com
Nicolas M F
NM
Øyane
Ståle
S
Pallesen
Bente Elisabeth
BE
Moen
Torbjörn
T
Akerstedt
Bjørn
B
Bjorvatn
D000328:Adult; D001008:Anxiety Disorders / Q000453:epidemiology / Q000523:psychology*; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000453:epidemiology / Q000523:psychology*; D005221:Fatigue / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006306:Health Surveys / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D009726:Nurses / Q000706:statistics & numerical data*; D009784:Occupational Diseases / Q000453:epidemiology / Q000523:psychology; D012044:Regression Analysis; D012647:Self-Assessment; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology / Q000523:psychology*; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology / Q000523:psychology*; D011795:Surveys and Questionnaires; D014940:Work Schedule Tolerance / Q000523:psychology*; D055815:Young Adult