This is the protocol for a review and there is no abstract. The objectives are as follows:
This review aims to identify which of the four interview tools has the best diagnostic test accuracy for diagnosing ASD in preschool children against the gold standard of multidisciplinary team clinical judgement. As it is inefficient to use more than one parent or carer report tool, the aims of this review are to assess the following.
1. Which of the parent or carer interview tools (ADI-R, GARS, DISCO, or 3di) has the best diagnostic test accuracy?
2. How does the diagnostic test accuracy of the best performing interview tool compare to the diagnostic test accuracy of the CARS?
2. How does the diagnostic test accuracy of the ADOS-G compare to the CARS?
3. Is the diagnostic test accuracy of any one test sufficient for it to be suitable as a sole assessment tool for preschool children?
4. Is there any combination of tests which, if offered in sequence, would provide suitable diagnostic test accuracy and enhance test efficiency?
5. If data are available, does a combination of an interview tool with a structured observation test have better diagnostic test accuracy (fewer false positives and fewer false negatives) than either test alone?
This review will evaluate diagnostic tests putting most weight on the specificity of the various index tests for the reasons outlined above.
1. Does any diagnostic test have greater diagnostic test accuracy in age-specific subgroups within the preschool age range?
2. Does any diagnostic test have greater diagnostic test accuracy for the different diagnostic subgroups, that is in differentiating Autistic Disorder/Childhood autism from other ASD?
Potential sources of heterogeneity include age of study participants; severity and type of diagnosis (Autistic Disorder or Childhood Autism versus PDD-NOS); presence or absence of language delay; presence or absence of intellectual disability or developmental delay; diagnostic mix of population included; prospective versus existing diagnosis; study type, and duration between diagnosis and diagnostic test accuracy studies being performed.