Abstract
Insomnia is common, is associated with major adverse medical and mental health outcomes, has a negative impact on quality of life, and has significant economic consequences. However, little is known about the global insomnia burden. This systematic review estimated the global prevalence of insomnia in adults. PubMed and Embase were searched (terms "insomnia," "prevalence," and "general population") to identify relevant peer-reviewed studies (final search 2-3 Sep 2024). Included studies had the highest data quality and lowest risk of bias, and reported clinically relevant insomnia prevalence in the general population. Insomnia prevalence estimates were applied to United Nations (UN) population data using a country-specific study (if available) or the highest-quality study (if no country-specific study). Of 1651 potential records, 18 studies (262,582 participants) were included. Thirty-one of 237 UN/World Bank-recognized countries/territories had a suitable nation-specific adult insomnia prevalence estimate. 852,325,091 adults (95 % confidence interval 830,354,161-874,309,252) were estimated to have insomnia (global prevalence: 16.2 %) and 414,967,941 were estimated to have severe insomnia (7.9 %). Insomnia and severe insomnia were more prevalent in females versus males across all age groups. The high global prevalence of insomnia disorder reinforces the need for comprehensive public health and clinical sleep health initiatives worldwide. REGISTRATION: PROSPERO: CRD42024581410.