Diagnostic Evaluation of Children with Autism Spectrum Disorders: Clinician Compliance with Published Guidelines.

To assess to what extent child neurologists (CNs) and developmental-behavioral pediatricians (DBPs) order diagnostic tests that are not recommended/indicated and/or fail to order tests that are recommended/indicated when evaluating children with an autism spectrum disorder (ASD). CNs and DBPs in the United States were asked which laboratory tests they would "routinely order" for a preschool child with ASD and IQ = 58 (ASD + Intellectual Disability (ID)), and a preschool child with ASD and IQ = 85 (ASD-ID). Chi-square tests were performed to identify differences (CNs vs DBPs) in laboratory testing. The sample consisted of 267 respondents (127 CN's; 140 DBPs). When evaluating ASD + ID or ASD - ID, inappropriate tests (≥1) were ordered by 76.8% and 76.4% of MDs, respectively. There was no significant difference between specialties in compliance with evaluation guidelines for ASD + ID (CN = 20.5% vs DBP = 16.4%; χ = 0.73). No significant differences were noted (DBP vs CN) regarding the percent ordering inappropriate tests for either clinical case or within each specialty when comparing testing for ASD + ID versus ASD - ID. Relative to DBPs, CNs were more likely to order EEGs and MRIs when evaluating children with ASD + ID or ASD - ID. 10% and 40% of respondents did not order any recommended genetic tests when evaluating ASD + ID and ASD - ID, respectively. When evaluating children with ASD, many CNs and DBPs fail to order tests that should be routinely performed and often order tests that are not routinely indicated yet are neither benign nor inexpensive. Recommended molecular genetic tests are often not ordered. Clinical guidelines must be updated and better promulgated.