Establishing the content validity of the Epworth Sleepiness Scale for Children and Adolescents in Prader-Willi syndrome

Abstract

Study objectives: Excessive daytime sleepiness is common in Prader-Willi syndrome (PWS), with prevalence ranging from 52% to 100%. The goal of this study was to establish the content validity (ie, evidence that an instrument measures an intended concept of interest) of the parent/caregiver version of the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD), a measure of daytime sleepiness, in PWS.

Methods: Qualitative, dyadic semistructured video interviews were conducted with 18 caregivers and their children with PWS from April to June 2020. Concept elicitation and cognitive interview techniques were implemented. Thematic analyses allowed for examination of themes and data patterns.

Results: All caregivers (mean age 49 years) were mothers of individuals with PWS who experienced troublesome daytime sleepiness (mean age 14 years). The most prevalent observable signs/symptoms of daytime sleepiness were sleepy/sleepiness (n = 17; 94.4%), tired/tiredness (n = 16; 88.9%), exhaustion/exhausted (n = 5; 27.8%), anxious/stressed (n = 5; 27.8%), irritable/frustrated (n = 5; 27.8%), having tantrums/outbursts (n = 5; 27.8%), and lethargy (n = 4; 22.2%). Daytime sleepiness impacted various aspects of health including mental, emotional, physical, and social well-being. When caregivers were asked about the activities associated with daytime sleepiness, all salient concepts elicited mapped to the ESS-CHAD; saturation was met after the first 4 interviews. Only 2 concepts, after physical exertion and while inactive/bored, did not map. Caregiver statements indicated that these concepts, although related to daytime activities, were atypical of daily routines. The ESS-CHAD was well understood and relevant to caregivers.

Conclusions: This study supports the content validity of the ESS-CHAD and its appropriateness for evaluating treatment efficacy of daytime sleepiness in PWS.

Citation: Patel VP, Patroneva A, Glaze DG, Davis K, Merikle E, Revana A. Establishing the content validity of the Epworth Sleepiness Scale for Children and Adolescents in Prader-Willi syndrome. J Clin Sleep Med. 2022;18(2):485-496.

Keywords: Prader-Willi syndrome; caregivers; patient-centered outcomes research; qualitative research; sleepiness.

Conflict of interest statement

All authors have reviewed and approved the final, submitted version of this manuscript. Work for this study was performed at Labcorp Drug Development, Gaithersburg, Maryland. This study was funded by Harmony Biosciences. A.P. and K.D. are employees of Harmony Biosciences. E.M. is an employee of Labcorp Drug Development (formerly Covance by Labcorp), which received consultancy fees from Harmony Biosciences. D.G.G. and A.R. are employees of the Baylor College of Medicine, are consultants to and participate in the Harmony Phase 2 clinical trial of pitolisant, and are involved with the TREND community. At the time this research was conducted and completed, V.P.P. was an employee of Labcorp Drug Development.

© 2022 American Academy of Sleep Medicine.

Figures

Figure 1. The Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD), as rated by parents/caregivers.

“Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD), parent/carer to answer” copyright © MW Johns. Reproduced with permission. Contact information and permission to use: Mapi Research Trust, Lyon, France, https://eprovide.mapi-trust.org.

Figure 2. Dyad selection process.

Figure 3. Conceptual framework for daytime sleepiness in Prader-Willi syndrome.

Concepts elicited from caregivers that are highlighted in green map to the items in the ESS-CHAD. The concepts highlighted in purple do not map directly onto the ESS-CHAD; these concepts, however, were closely linked to care recipients’ daytime activities but were atypical of daily routines, based on caregiver statements. ESS-CHAD = Epworth Sleepiness Scale for Children and Adolescents.