title: Validation of a questionnaire to screen for shift work disorder.
abstract: OBJECTIVE
  At least 15% of the full-time work force is shift workers. Working during the overnight hours, early morning start times, and variable or rotating schedules present a challenge to the circadian system, and these shifts are associated with adverse health and safety consequences. Shift work disorder (SWD), a primary (circadian rhythm) sleep disorder indicated by excessive daytime sleepiness and/or insomnia associated with a shiftwork schedule, is under-recognized by primary care physicians. We sought to develop and validate a questionnaire to screen for high risk of SWD in a shift working population.
  
  
  METHODS
  Shift workers completed a 26-item questionnaire and were evaluated by a sleep specialist (physician) who diagnosed them as either positive or negative for SWD. The physician assessment of SWD was guided by a flow chart that operationalized the ICSD-2 criteria for SWD.
  
  
  METHODS
  18 sleep clinics in the USA.
  
  
  METHODS
  311 shift workers.
  
  
  METHODS
  Not applicable.
  
  
  RESULTS
  Responses to the items in the questionnaire were entered into a series of discrimination function analyses to determine the diagnostic value of the items and the fewest number of questions with the best predictive value. The function was then cross-validated. A final 4-item questionnaire has 89% positive predictive value and 62% negative predictive value (sensitivity = 0.74; specificity = 0.82).
  
  
  CONCLUSIONS
  This Shiftwork Disorder Screening Questionnaire may be appropriate for use in primary care settings to aid in the diagnosis of SWD.
authors.affiliation: Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. lkbarger@hms.harvard.edu
authors.forename: Laura K
authors.initials: LK
authors.lastname: Barger
authors.forename: Rowan P
authors.initials: RP
authors.lastname: Ogeil
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Drake
authors.forename: Conor S
authors.initials: CS
authors.lastname: O'Brien
authors.forename: Kim T
authors.initials: KT
authors.lastname: Ng
authors.forename: Shantha M W
authors.initials: SM
authors.lastname: Rajaratnam
mesh_terms: D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D016002:Discriminant Analysis; D005260:Female; D017144:Focus Groups; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D020178:Sleep Disorders, Circadian Rhythm / Q000175:diagnosis*; D011795:Surveys and Questionnaires; D013997:Time Factors; D014940:Work Schedule Tolerance; D055815:Young Adult