Discriminant Validity of the Autism Spectrum Screening Questionnaire Parent Form to Preschool Children

Background:The Autism Spectrum Screening Questionnaire(ASSQ;Ehlers et al.,1999) was developed to screen school children for HF-ASD. Although the ASSQ consists of only 27 items, it has shown both validity and reliability, with good sensitivity and specificity in clinical settings. Although the ASSQ has been psychometrically tested in only 7-16-year-old children, an application for younger children than 7-year-old is also expected to make early detection of HF-ASD and prevent secondary maladjustment of them. There have been reports of ASSQ being used for six-year-olds in other studies and earlier practical clinical usages(Kopp et al.,2011). As such, it is important to examine the scale’s psychometric properties and discriminant validity, especially when considering the application of the instrument at an earlier age.

Objectives:This study examined the psychometric properties of applying the ASSQ for preschool children.

Methods:Two groups of children took part in the current study. The first “community” group(N=1390) who were recruited from a Hirosaki Five-year-old Child Developmental Health Check-up Study, which assessed the mental health of children in the city, from 2013 to 2016. The questionnaires were sent to the parents of five-year-old children after which those who agreed to participate in the study(through their informed consent) answered the questionnaires and sent them back to the municipal health center. The response rate was 74.6%. The second “clinical” group consisted of children from affiliated research centers with Graduate School of Medicine, Hirosaki University. This group consisted of 60 children diagnosed ASD and 94 children with Non-ASD neuropsychiatric diagnoses.

Results:There was a good internal consistency for the ASSQ in both the clinical and community group with Cronbach’s alpha of .844-.881. The results from Kruskal-Wallis tests, only one item “Is old-fashioned or precocious” was not able to discriminate between ASD and Community group. Meanwhile, in 19 of 27 items, there was a difference in scores between the ASD and the Non-ASD group, so that certain discriminant validity was also shown within the clinical group. ROC analyses revealed the full extent of the scale’s ability to distinguish children with ASD against community children with an area of 0.960 under the curve(95%CI: 0.939–0.981). A score of 6.5 on the ASSQ had a sensitivity of 0.933 and a specificity of 0.835 when it is used as a primary screening tool. On the other hand, discriminatory power within clinical groups was lower than discriminant power of the ASSQ in distinguishing the ASD from the Community children(AUC=0.749, 95%CI=0.671–0.826). A score of 6.5 had a sensitivity of 0.933 and a specificity of 0.319, while a score of 13.5 resulted in sensitivity reducing to 0.650 but specificity increasing to 0.734.

Conclusions:The results showed that, just like in the case of school-aged children, the ASSQ had reliability and validity as a screening instrument in both community and clinical settings for pre-school children. However, the analysis of the ASSQ subscale items showed that only for number 1, namely, “Is old-fashioned or precocious,” the score of the community group was higher than that of the ASD group; this revealed the possibility that this decreased the discriminant validity.