Comparing Treatment Effect Measurements in Narcolepsy: The Sustained Attention to Response Task, Epworth Sleepiness Scale and Maintenance of Wakefulness Test

Abstract

Study objectives: To validate the Sustained Attention to Response Task (SART) as a treatment effect measure in narcolepsy, and to compare the SART with the Maintenance of Wakefulness Test (MWT) and the Epworth Sleepiness Scale (ESS).

Design: Validation of treatment effect measurements within a randomized controlled trial (RCT).

Patients: Ninety-five patients with narcolepsy with or without cataplexy.

Interventions: The RCT comprised a double-blind, parallel-group, multicenter trial comparing the effects of 8-w treatments with pitolisant (BF2.649), modafinil, or placebo (NCT01067222). MWT, ESS, and SART were administered at baseline and after an 8-w treatment period. The severity of excessive daytime sleepiness and cataplexy was also assessed using the Clinical Global Impression scale (CGI-C).

Measurements and results: The SART, MWT, and ESS all had good reliability, obtained for the SART and MWT using two to three sessions in 1 day. The ability to distinguish responders from nonresponders, classified using the CGI-C score, was high for all measures, with a high performance for the SART (r = 0.61) and the ESS (r = 0.54).

Conclusions: The Sustained Attention to Response Task is a valid and easy-to-administer measure to assess treatment effects in narcolepsy, enhanced by combining it with the Epworth Sleepiness Scale.

Keywords: ESS; MWT; SART; narcolepsy; sleepiness; sustained attention; treatment effects; validation; vigilance.