title: Cross-cultural and comparative epidemiology of insomnia: the Diagnostic and statistical manual (DSM), International classification of diseases (ICD) and International classification of sleep disorders (ICSD).
abstract: OBJECTIVE
  To compare the prevalence of insomnia according to symptoms, quantitative criteria, and Diagnostic and Statistical Manual of Mental Disorders, 4th and 5th Edition (DSM-IV and DSM-5), International Classification of Diseases, 10th Revision (ICD-10), and International Classification of Sleep Disorders, 2nd Edition (ICSD-2), and to compare the prevalence of insomnia disorder between Hong Kong and the United States by adopting a similar methodology used by the America Insomnia Survey (AIS).
  
  
  METHODS
  Population-based epidemiological survey respondents (n = 2011) completed the Brief Insomnia Questionnaire (BIQ), a validated scale generating DSM-IV, DSM-5, ICD-10, and ICSD-2 insomnia disorder.
  
  
  RESULTS
  The weighted prevalence of difficulty falling asleep, difficulty staying asleep, waking up too early, and non-restorative sleep that occurred ≥3 days per week was 14.0%, 28.3%, 32.1%, and 39.9%, respectively. When quantitative criteria were included, the prevalence dropped the most from 39.9% to 8.4% for non-restorative sleep, and the least from 14.0% to 12.9% for difficulty falling asleep. The weighted prevalence of DSM-IV, ICD-10, ICSD-2, and any of the three insomnia disorders was 22.1%, 4.7%, 15.1%, and 22.1%, respectively; for DSM-5 insomnia disorder, it was 10.8%.
  
  
  CONCLUSIONS
  Compared with 22.1%, 3.9%, and 14.7% for DSM-IV, ICD-10, and ICSD-2 in the AIS, cross-cultural difference in the prevalence of insomnia disorder is less than what is expected. The prevalence is reduced by half from DSM-IV to DSM-5. ICD-10 insomnia disorder has the lowest prevalence, perhaps because excessive concern and preoccupation, one of its diagnostic criteria, is not always present in people with insomnia.
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: kfchung@hkucc.hku.hk.
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: Chung
authors.affiliation: School of Chinese Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Wing-Fai
authors.initials: WF
authors.lastname: Yeung
authors.affiliation: Department of Psychology, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Fiona Yan-Yee
authors.initials: FY
authors.lastname: Ho
authors.affiliation: Department of Psychology, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Kam-Ping
authors.initials: KP
authors.lastname: Yung
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Yee-Man
authors.initials: YM
authors.lastname: Yu
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Chi-Wa
authors.initials: CW
authors.lastname: Kwok
mesh_terms: D003431:Cross-Cultural Comparison; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology*; D056508:Sleep Medicine Specialty / Q000592:standards; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
keywords: DSM-5; DSM-IV-TR; ICD-10; ICSD-2; Insomnia; Prevalence