title: How useful is the Social Communication Questionnaire in toddlers at risk of autism spectrum disorder?
abstract: BACKGROUND
  The Social Communication Questionnaire (SCQ) is a screening instrument with established validity against the Autism Diagnostic Interview-Revised (ADI-R) in children aged 4 years and older. Indices of diagnostic accuracy have been shown to be strong in school-aged samples; however, relatively little is known about the performance of the SCQ in toddlers at risk of autism spectrum disorder (ASD).
  
  
  METHODS
  This study replicates and extends previous research by Corsello et al. (2007) in a comparatively large (N = 208), substantially younger (20-40 months) sample of children at high risk of ASD. The usefulness of the SCQ as a second-level screening instrument with different cut-off scores was evaluated in relation to IQ, age, and type of ASD diagnosis. The use of the SCQ as compared to the ADI-R was evaluated against clinical diagnosis, both alone and in combination with the ADOS.
  
  
  RESULTS
  The SCQ with different cut-offs consistently showed an unsatisfactory balance between sensitivity and specificity in screening for ASD in high-risk toddlers, with only a few exceptions for specific age, IQ, or diagnostic groups. Even though the SCQ and ADI-R were highly correlated, diagnostic agreement with the best evidence clinical diagnosis was poor for both measures. The ADOS used alone consistently had the highest predictive value. For autism versus not-autism, the combined SCQ and ADOS performed as well as the ADOS alone and notably better than the combination ADI-R and ADOS.
  
  
  CONCLUSIONS
  The SCQ is likely to result in a number of false-positive findings, particularly in children with autism symptomatology, and the balance between sensitivity and specificity is poor. The ADOS should be considered the most valid and reliable diagnostic instrument in these very young at-risk children.
authors.affiliation: Karakter Child and Adolescent Psychiatry University Centre, Reinier Postlaan 12, Nijmegen, The Netherlands. i.oosterling@karakter.com
authors.forename: Iris
authors.initials: I
authors.lastname: Oosterling
authors.forename: Nanda
authors.initials: N
authors.lastname: Rommelse
authors.forename: Maretha
authors.initials: M
authors.lastname: de Jonge
authors.forename: Rutger Jan
authors.initials: RJ
authors.lastname: van der Gaag
authors.forename: Sophie
authors.initials: S
authors.lastname: Swinkels
authors.forename: Sascha
authors.initials: S
authors.lastname: Roos
authors.forename: Janne
authors.initials: J
authors.lastname: Visser
authors.forename: Jan
authors.initials: J
authors.lastname: Buitelaar
mesh_terms: D002659:Child Development Disorders, Pervasive / Q000175:diagnosis*; D002675:Child, Preschool; D003142:Communication; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D007360:Intelligence; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012919:Social Behavior; D011795:Surveys and Questionnaires / Q000706:statistics & numerical data*