title: What is the preferred number of consecutive night shifts? results from a crossover intervention study among police officers in Denmark.
abstract: Among police officers in Denmark, we studied (i) how many consecutive night shifts participants preferred at baseline; (ii) preferences regarding three intervention conditions (two, four, and seven consecutive night shifts followed by the same number of days off/day shifts: '2 + 2', '4 + 4', '7 + 7') at follow-up; (iii) characteristics of participants preferring each of these intervention conditions. Questionnaire data from a crossover intervention study were used (baseline: n = 73; follow-up: n = 68). At baseline, 49% preferred four consecutive night shifts. At follow-up, 57% preferred '4 + 4', 26% preferred '2 + 2' and 26% preferred '7 + 7'. Participants, who preferred longer spells of night work experienced that night work was less demanding, found it easier to sleep at different times of the day, and were more frequently evening types compared with participants who preferred shorter spells of night work. The participants' preferences are likely to be influenced by their previous shift work experience. Practitioner Summary: We investigated police officers' preferences regarding the number of consecutive night shifts. The majority preferred four consecutive night shifts. Those who preferred the longer spells of night work found night work less demanding, found it easier to sleep at different times of the day, and were more frequently evening types.
authors.affiliation: a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Nabe-Nielsen
authors.affiliation: a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark.|b The National Research Centre for the Working Environment , Copenhagen , Denmark.
authors.forename: Marie Aarrebo
authors.initials: MA
authors.lastname: Jensen
authors.affiliation: a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark.|b The National Research Centre for the Working Environment , Copenhagen , Denmark.
authors.forename: Åse Marie
authors.initials: ÅM
authors.lastname: Hansen
authors.affiliation: b The National Research Centre for the Working Environment , Copenhagen , Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Kristiansen
authors.affiliation: a Department of Public Health, Section of Social Medicine , University of Copenhagen, Centre for Health and Society , Copenhagen , Denmark.|b The National Research Centre for the Working Environment , Copenhagen , Denmark.
authors.forename: Anne Helene
authors.initials: AH
authors.lastname: Garde
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002318:Cardiovascular Diseases; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D003718:Denmark; D006801:Humans; D007588:Job Satisfaction; D008297:Male; D008875:Middle Aged; D016495:Police / Q000523:psychology* / Q000706:statistics & numerical data; D011788:Quality of Life / Q000523:psychology*; D012307:Risk Factors; D012890:Sleep; D011795:Surveys and Questionnaires; D014940:Work Schedule Tolerance / Q000502:physiology / Q000523:psychology*
keywords: Chronotype; employee preferences; schedule fit; shift work; sleep flexibility