Patient-reported outcome measure for central disorders of hypersomnolence (PROM-CDH): development and validation

Central disorders of hypersomnolence (CDH) have a major impact on patients' quality of life (QoL). We developed and validated a disease-specific patient-reported outcome measure (PROM) to measure QoL in CDH: the PROM-CDH, for adults with narcolepsy types 1 and 2 (NT1 and NT2), and idiopathic hypersomnia (IH).

The developmental process involved focus groups and interviews with adults with CDH (n = 27), family members (n = 8) and sleep medicine specialists (n = 5). In the quantitative evaluation, the draft version of the PROM-CDH, together with the Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Hospital Anxiety and Depression Scale (HADS), ADHD rating scale (ADHD-RS) and the 36-item Short Form (SF-36) were filled out online by N = 369 patients with (suspected) CDH.

Internal consistency was good for the total group and within diagnostic groups (all Cronbach's α > .8). Age was positively (β = .11; p = .003), and female gender (β = -3.67; p = .002), comorbid sleep apnea (β = -4.77; p = .005), and depression (β = -12.71; p < .001) were negatively associated with the PROM-CDH score. Exploratory and confirmatory factor analyses resulted in five subscales. Convergent validity showed highest correlation between the PROM-CDH total score and HADS Depression (r = -.71; p < .01); and the SF-36 subscales Emotional wellbeing (r = .65; p < .01) and Energy/fatigue (r = .71; p < .01). Additional adjustments including content validity in consensus rounds resulted in the final PROM-CDH (version 1, 2023).

The PROM-CDH has high potential in clinical practice for patients with CDH, to support clinical care, as an important outcome in clinical trials, and as a sleep care quality indicator. Further international validation is ongoing, and it is freely available in multiple languages.