Diagnosed Prevalence of Idiopathic Hypersomnia Among Adults in the United States

This work was sponsored by Jazz Pharmaceuticals Introduction: Idiopathic hypersomnia (IH) is a neurologic disorder characterized by excessive daytime sleepiness, sleep inertia, prolonged nighttime sleep, long and unrefreshing naps, and cognitive dysfunction. Limited research reports the burden of IH. This study estimated the diagnosed prevalence of IH among US adults (2019‒2021). Methods: Symphony Integrated Dataverse® claims (11/2015‒12/2021) were analyzed. Eligible patients were aged ≥18 years and had 1 medical or prescription claim in the year of interest (2019, 2020, 2021) and in the year prior. Diagnosed prevalence included all IH cases from eligible patients through the last day of the year of interest. IH cases had ≥1 medical claim containing an IH diagnosis code (ICD-9-CM, 327.11, 327.12; ICD-10-CM, G47.11, G47.12) in any position before or during the year of interest, and without cataplexy. Unweighted prevalence estimates were reported per 100,000 persons (95% CIs). Age- and sex-adjusted prevalence estimates were calculated (2019 US Census Bureau). Results: Over 158, 168, and 187 million adults were assessed for diagnosed prevalence of IH in each respective year (2019‒2021). The unweighted diagnosed prevalence of IH was 32.1 per 100,000 persons (2019; CI: 31.8-32.4), 35.7 per 100,000 persons (2020; CI: 35.4-36.0), and 37.0 per 100,000 persons (2021; CI: 36.8-37.3). The estimated standardized numbers of US adults diagnosed with IH were 80,603 (2019; CI: 80,048-81,161), 89,539 (2020; CI: 88,954-90,127), and 92,139 (2021; CI: 91,545-92,736). Conclusion: Prevalence of IH in US adults increased 15.3% from 2019‒2021, compared to a previously reported increase of 32% from 2013‒2016. Future research may elucidate the causes of continued increases.