P126 Systematic review of outcome measures used in narcolepsy clinical trials

Treatment of the sleep disorder narcolepsy is primarily symptomatic. With limited population data and insufficient systems to capture patient data, a greater emphasis has been placed on the patient perspective in determining satisfaction and treatment success in clinical settings. While Randomised Controlled Trials (RCTs) are considered the gold standard when determining treatment effectiveness, how effectiveness is measured in a narcolepsy population remains unknown. Therefore, we aimed to explore the outcome measures used in narcolepsy RCTs, and further evaluate the adequacy of any self-reported outcome measures used. Methods Electronic databases (MEDLINE, EMBASE, CINAHL, SCOPUS, PSYCHINFO) and clinicaltrials.gov were searched in April 2020, with primary and secondary outcomes extracted from eligible studies. Self-reported outcome measures used at least once as a primary outcome measure were further explored, with validation studies of these systematically searched for (using the above databases) and analysed using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) Risk of Bias tool. Results We identified 82 published RCTs involving patients with narcolepsy, of which 35 objective and 46 subjective measures were used. Of these, the Maintenance of Wakefulness Test (n=29), Epworth Sleepiness Scale (ESS) (n=14) and Multiple Sleep Latency Test (n=9) were the most frequently selected primary outcome measures. While our analysis of self-reported outcome measures is ongoing, preliminary results suggest that few have been adequately validated in a narcolepsy-specific population. Discussion Our preliminary results identify a high level of heterogeneity between outcome measures used in RCTs, thus difficult to draw conclusions and compare interventions.