Background: Although several diagnostic systems define insomnia, little is known about the implications of using one versus another of them.

Methods: The America Insomnia Survey, an epidemiological survey of managed health care plan subscribers (n = 10,094), assessed insomnia with the Brief Insomnia Questionnaire, a clinically validated scale generating diagnoses according to DSM-IV-TR; International Statistical Classification of Diseases, Tenth Revision (ICD-10); and Research Diagnostic Criteria/International Classification of Sleep Disorders, Second Edition (RDC/ICSD-2) criteria. Regression analysis examines associations of insomnia according to the different systems with summary 12-item Short-Form Health Survey scales of perceived health and health utility.

Results: Insomnia prevalence estimates varied widely, from 22.1% for DSM-IV-TR to 3.9% for ICD-10 criteria. Although ICD insomnia was associated with significantly worse perceived health than DSM or RDC/ICSD insomnia, DSM-only cases also had significant decrements in perceived health. Because of its low prevalence, 66% of the population-level health disutility associated with overall insomnia and 84% of clinically relevant cases of overall insomnia were missed by ICD criteria.

Conclusions: Insomnia is highly prevalent and associated with substantial decrements in perceived health. Although ICD criteria define a narrower and more severe subset of cases than DSM criteria, the fact that most health disutility associated with insomnia is missed by ICD criteria, while RDC/ICSD-only cases do not have significant decrements in perceived health, supports use of the broader DSM criteria.

Roth T, Coulouvrat C, Hajak G, Lakoma MD, Sampson NA, Shahly V, Shillington AC, Stephenson JJ, Walsh JK, Kessler RC. Prevalence and perceived health associated with insomnia based on DSM-IV-TR; International Statistical Classification of Diseases and Related Health Problems, Tenth Revision; and Research Diagnostic Criteria/International Classification of Sleep Disorders, Second Edition criteria: results from the America Insomnia Survey. Biol Psychiatry. 2011 Mar 15;69(6):592-600. doi: 10.1016/j.biopsych.2010.10.023. Epub 2010 Dec 31. PMID: 21195389.