The Sleep Condition Indicator: a clinical screening tool to evaluate insomnia disorder

BMJ Open. 2014 Mar 18;4(3):e004183. doi: 10.1136/bmjopen-2013-004183.


Objective: Describe the development and psychometric validation of a brief scale (the Sleep Condition Indicator (SCI)) to evaluate insomnia disorder in everyday clinical practice.

Design: The SCI was evaluated across five study samples. Content validity, internal consistency and concurrent validity were investigated.

Participants: 30 941 individuals (71% female) completed the SCI along with other descriptive demographic and clinical information.

Setting: Data acquired on dedicated websites.

Results: The eight-item SCI (concerns about getting to sleep, remaining asleep, sleep quality, daytime personal functioning, daytime performance, duration of sleep problem, nights per week having a sleep problem and extent troubled by poor sleep) had robust internal consistency (α≥0.86) and showed convergent validity with the Pittsburgh Sleep Quality Index and Insomnia Severity Index. A two-item short-form (SCI-02: nights per week having a sleep problem, extent troubled by poor sleep), derived using linear regression modelling, correlated strongly with the SCI total score (r=0.90).

Conclusions: The SCI has potential as a clinical screening tool for appraising insomnia symptoms against Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria.

Keywords: Psychiatry; Sleep Medicine.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Female
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Psychometrics / methods
  • Reproducibility of Results
  • Severity of Illness Index
  • Sleep Initiation and Maintenance Disorders / diagnosis*
  • Sleep Wake Disorders
  • Sleep*
  • Surveys and Questionnaires / standards*
  • Young Adult