Burden among participants with central disorders of hypersomnolence in six European countries

BACKGROUND: Narcolepsy types 1 and 2 (NT1/NT2) and idiopathic hypersomnia (IH) are central disorders of hypersomnolence (CDHs) that significantly impact patients' quality of life (QoL). We investigated the recent medication use, comorbidities, and clinical burden among participants with CDHs from six European countries. METHODS: In this cross-sectional observational study, self-reported data were collected from adults with CDHs using a three-part survey. Assessed endpoints included the Epworth Sleepiness Scale (ESS), Narcolepsy Severity Scale for Clinical Trials (NSS-CT), IH Severity Scale (IHSS), and EuroQoL-5 dimension-5 level (EQ-5D-5L). EQ-5D health state utilities were evaluated by ESS category to measure the impact of symptom severity. RESULTS: Of 2797 surveys, 1818 (65%) were completed (NT1, 51.1%; NT2, 11.2%; IH, 19.9%; undefined CDH, 17.8%). Most participants reported receiving narcolepsy/IH medication in the past 30 days (NT1, 91.3%/NT2, 84.5%/IH, 79.4%). The most common comorbidities were back pain (NT1, 27.4%/NT2, 25.5%/IH, 30.4%), headache/migraine (22.4%/27.2%/34.7%), and depression (22.5%/24.5%/29.5%). For NT1/NT2/IH, mean (interquartile range) ESS total scores were 15.5 (12-19)/14.4 (11-18)/13.6 (10-17), NSS-CT scores (excluding cataplexy items) were 17.4 (11-23)/14.6 (9-20)/12.1 (7-17), IHSS scores were 27.0 (20-34)/27.5 (22-35)/32.4 (27-38), and EQ-5D VAS scores were 62.4 (50-78)/63.6 (50-79)/61.0 (48-79). Mean (SD) health state utilities decreased from 0.914 (0.152) in the lowest ESS category to 0.726 (0.259) in the highest (severe) ESS total score category. CONCLUSIONS: These findings underscore the ongoing clinical burden in individuals with CDHs, including those receiving treatment. Symptom persistence and QoL impacts highlight the limitations of current treatments and the need for more comprehensive management strategies for CDHs.