The Prevalence of Insomnia Disorder in the General Population: A Meta-Analysis.

Insomnia disorder is a significant public health issue, but the prevalence estimates vary widely. We performed a meta-analysis aiming to pool prevalence rates in studies (1) carried out in the general population (2) using a true random sample (3) and using a diagnostic interview, DSM based self-report questions, or a questionnaire with a cut-off established against the DSM criteria. A literature search (in PubMed, Embase, APA PsycInfo) was performed up to April 2024. Two independent reviewers assessed title and abstracts (n = 6732), full-text manuscripts (n = 621) and extracted the data of the 47 included studies. Prevalence rates were pooled using a three-level hierarchical random-effects model, stratified by diagnosis type and adjusted for gender distribution and mean sample age. The pooled prevalence of all studies using an interview to establish the DSM criteria was 12.4% (95% CI: 9.0-16.8%), and of self-report questions assessing the DSM diagnosis 16.3% (95% CI: 11.3%-23.0%). There were 27 studies using different insomnia questionnaires with different cut-offs (prevalence range 7.5%-32.3%). The prevalences differed significantly across regions and high quality studies yielded a lower prevalence rates than lower quality studies. This meta-analysis confirms that insomnia is a common disorder with a prevalence of 12.4 as the most accurate estimate. It also shows the need for standardised ways of assessing insomnia. We think the golden standard is using standardised structured clinical interviews. However, if this is not feasible, we recommend using well validated questionnaires such as the Sleep Condition Indicator or the Insomnia Severity Index. Trial Registration: PROSPERO CRD42023402745.