P027 Insights from a 10-year Australasian consumer data registry study.

INTRODUCTION: Idiopathic hypersomnia (IH) is a disorder of central hypersomnolence that results in excessive daytime sleepiness in the absence of another identifying cause. Case studies from sleep clinic patients have guided current knowledge but may not be a fair representation of the wider population of IH diagnoses. This study aims to better characterize patients diagnosed with IH in Australasia using online survey data. METHODS: A retrospective analysis of 686 participants from the Hypersomnolence Australia Consumer Data Registry sleep physician diagnosed with either IH (n = 554) or narcolepsy (NC) (n = 132) between January 2013 and January 2023 was performed. RESULTS: IH participants (98.9% had MSLT) reported additional sleep disorders such as OSA (16.4%) and restless leg syndrome (7.9%) and notable comorbidities included depression (46.2%) and anxiety (50%). Forty-two percent of IH participants were diagnosed after turning 33 years of age (compared to NC participants, 31.8%). The IH group reported more unrefreshing sleep, sleep drunkenness and the NC group reported more excessive sleepiness, hallucinations, sleep paralysis and automatic behaviour (all p values < 0.001). The most frequently used medication in both groups was dexamphetamine (IH = 44.2%, NC = 47.7%) but participants from the IH group were prescribed more modafinil and less armodafinil and sodium oxybate (p values < 0.001) than patients with NC. Further analyses are in preparation. DISCUSSION: This study demonstrates the value of consumer registries to better characterize symptomatology and co-morbidities in IH and NC and further research in these conditions.