The ESS was developed initially for use among adults. However, the (adult) ESS has also been used successfully among adolescents, with thousands of respondents in some studies (MÃ¼ller at al, 2002; Shin et al, 2003; Gibson et al, 2006; Chung et al, 2008; Danner et al, 2008; Choi et al, 2009). Other investigators have used one of many different modified versions of the ESS, some with a wider age-range including younger children (Snow et al, 2002; Joo et al, 2005; Campbell et al, 2007; Melendres et al 2007; Anderson et al, 2009; Chan et al, 2009; Moore et al, 2009; James et al, 2011; Storfer-Isser et al, 2013).
Several of the modified versions of the ESS have been shown to be internally consistent (eg. with Cronbachâ€™s alpha >0.75) and to have significant external criterion validity, especially in relation to academic achievement at school. Their use has indicated that the concept of daytime sleepiness, in the sense of ASP as measured by the ESS, is valid for children and adolescents as it is for adults. However, the results of many of those earlier investigations cannot be directly compared with one another because they used different questionnaires. In addition, none of the previously modified versions of the ESS was authorised by the copyright holder. To overcome these difficulties Dr Johns has developed a new standardised and authorised version of the ESS for children and adolescents, the ESS-CHAD, (Johns, 2015).
Development of the ESS-CHAD
The ESS-CHAD is very similar to the adult ESS, but with minor changes to the instructions and descriptions of some of the activities, making them more easily comprehended and more likely to be within the experience of children and adolescents. The recall interval is more clearly specified as â€˜over the last monthâ€™. The reference to alcohol is omitted from question 7, and â€˜a classroom at schoolâ€™ is specified as the public place in question 3. Question 8 is replaced by a question asking about falling asleep while â€˜sitting and eating a mealâ€™.
The same conceptual framework is used for the ESS-CHAD as for the adult ESS, and they are scored the same way. The activities in both questionnaires have the same relative somnificities. The reference range of â€˜normalâ€™ scores is believed to be the same, but that needs confirmation. Most children over the age of about nine years, and most adolescents, can answer the ESS-CHAD without assistance. Most younger children require parental assistance, or a parent/carer can answer the questionnaire for them.
A sample copy of the ESS-CHAD (English for Australia version) is available here in pdf.