Validation of the autism spectrum screening questionnaire in a total population sample.

There is a lack of instruments validated for screening of autism spectrum disorders (ASD) in general populations and primary care settings. The Autism Spectrum Screening Questionnaire (ASSQ) has previously been shown to have good screening properties in clinical settings. We used the ASSQ to screen a total population of 7-9 year-olds (N = 9430) for ASD in the Bergen Child Study. Parents and teachers filled in the ASSQ, and high-scorers were invited for clinical assessment, along with a large group of screen negative children. We found that the ASSQ was well suited as a general population screen. Combining parent and teacher ASSQ and using cut-off score of > or =17 provided the most efficient screen with sensitivity of 0.91 and specificity of 0.86.