title: Sleep-wake time perception varies by direct or indirect query.
abstract: OBJECTIVE
  The diagnosis of insomnia rests on self-report of difficulty initiating or maintaining sleep. However, subjective reports may be unreliable, and possibly may vary by the method of inquiry. We investigated this possibility by comparing within-individual response to direct versus indirect time queries after overnight polysomnography.
  
  
  METHODS
  We obtained self-reported sleep-wake times via morning questionnaires in 879 consecutive adult diagnostic polysomnograms. Responses were compared within subjects (direct versus indirect query) and across groups defined by apnea-hypopnea index and by self-reported insomnia symptoms in pre-sleep questionnaires. Direct queries required a time duration response, while indirect queries required clock times from which we calculated time durations.
  
  
  RESULTS
  Direct and indirect queries of sleep latency were the same in only 41% of cases, and total sleep time queries matched in only 5.4%. For both latency and total sleep, the most common discrepancy involved the indirect value being larger than the direct response. The discrepancy between direct and indirect queries was not related to objective sleep metrics. The degree of discrepancy was not related to the presence of insomnia symptoms, although patients reporting insomnia symptoms showed underestimation of total sleep duration by direct response.
  
  
  CONCLUSIONS
  Self-reported sleep latency and total sleep time are often internally inconsistent when comparing direct and indirect survey queries of each measure. These discrepancies represent substantive challenges to effective clinical practice, particularly when diagnosis and management depends on self-reported sleep patterns, as with insomnia. Although self-reported sleep-wake times remains fundamental to clinical practice, objective measures provide clinically relevant adjunctive information.
authors.affiliation: Department of Neurology, Sleep Division, Massachusetts General Hospital, Boston MA:
authors.forename: Y
authors.initials: Y
authors.lastname: Alameddine
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, MD.
authors.forename: J M
authors.initials: JM
authors.lastname: Ellenbogen
authors.affiliation: Department of Neurology, Sleep Division, Massachusetts General Hospital, Boston MA: Division of Sleep Medicine, Harvard Medical School, Boston, MA.
authors.forename: M T
authors.initials: MT
authors.lastname: Bianchi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D057566:Self Report; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis*; D011795:Surveys and Questionnaires; D013998:Time Perception; D055815:Young Adult
keywords: inconsistency; self-report; subjective; time perception