Psychometric Properties of Patient-Reported Outcome Measures Among Patients With Narcolepsy

Findings published in Sleep showed little evidence for validity, reliability, and responsiveness of patient-reported outcome measures regularly used to assess treatment efficacy in narcolepsy.  

Researchers sought to measure efficacy of narcolepsy interventions in randomized controlled trials among adults and children and examine psychometric properties of patient-reported outcome measures.

Objective and subjective outcome measures from narcolepsy randomized controlled trials was extracted from clinical trial registries and bibliographical databases. For trials that included patient-reported outcome measures, researchers additionally “searched for psychometric studies conducted in a narcolepsy population using bibliographical databases and appraised using Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines.”

Across 100 randomized controlled trials, 80 different outcome measures were used, but Epworth Sleepiness Scale (ESS) (n=49) and Maintenance of Wakefulness Test (n=47) were most frequent.

“We found 19 validation studies of 10 patient-reported outcome measures in narcolepsy populations,” wrote study authors. “There was limited evidence for validity or responsiveness of the ESS; yet sufficient reliability (pooled ICC: 0.81-0.87).”

Sufficient reliability (pooled ICC: 0.71-0.92) was found in the Narcolepsy Severity Scale (NSS) as well as sufficient discriminated validity both treated and untreated among adult and pediatric versions.

In pediatric populations content validity was evaluated for ESS for Children and Adolescents and NSS-P but rated inconclusive. For all scales, quality of evidence of the psychometric studies ranged from low to very low.

"The field needs to establish patient-centered minimal clinically important difference for the patient-reported outcome measures used in these trials," concluded researchers.

Reference:
Schokman, A, Sun Bin Y, Naehrig D, Cheung JMY, Kairaitis K, Glozier N. Evaluation of psychometric properties of patient-reported outcome measures frequently used in narcolepsy randomized controlled trials: a systematic review. Sleep. 2022;zsac156. doi:10.1093/sleep/zsac156