I thought this new study was interesting because it reveals that the instruments ("tests") used to evaluate individuals for autism differ in quality. Some work reasonable well, while others should either be revised or abandoned.
The instruments tested were those administered by caregivers, not researchers or clinicians. That means these are not the battery of instruments used during a neuro-psychological screening. A "level 2" screening is one that parents, educators, or trained caregivers give to determine if more screening is necessary. A level 2 instrument is not definitive and can only, at best, identify individuals who should undergo further evaluation.
Screening Accuracy of Level 2 Autism Spectrum Disorder Rating Scales: A Review of Selected Instruments
Autism, Vol. 14, No. 4, 263-284 (2010)
Megan Norris and Luc Lecavalier
Nisonger Center and Department of Psychology, The Ohio State University
The goal of this review was to examine the state of Level 2, caregiver-completed rating scales for the screening of AutismSpectrum Disorders (ASDs) in individuals above the age of three years. We focused on screening accuracy and paid particular attention to comparison groups. Inclusion criteria required that scales be developed post ICD-10, be ASD-specific, and have published evidence of diagnostic validity in peer-reviewed journals. The five scales reviewed were: the Social Communication Questionnaire (SCQ), Gilliam Autism Rating Scale/Gilliam Autism Rating Scale-SecondEdition (GARS/GARS-2), Social Responsiveness Scale (SRS), Autism Spectrum Screening Questionnaire (ASSQ), and Asperger Syndrome Diagnostic Scale (ASDS). Twenty total studies were located, most examining the SCQ. Research on the other scales was limited. Comparisons between scales were few and available evidence of diagnostic validity is scarce for certain subpopulations (e.g., lower functioning individuals, PDDNOS). Overall, the SCQ performed well, the SRS and ASSQ showed promise, and the GARS/GARS-2 and ASDS demonstrated poor sensitivity. This review indicates that Level 2 ASD caregiver-completed rating scales are in need of much more scientific scrutiny.I know some schools do use GARS and ASDS to determine program eligibility. Unfortunately, some school counselors (generally not clinicians) do view these as definitive tests. Thankfully, that is rare -- most schools and special programs know any level 2 instrument should only be used to consider a further referral for evaluation.