Diagnostic YIELD of ASD Arena Assessment MODEL

Background: An increasing number of young children are referred for assessment of possible Autism Spectrum Disorder (ASD). Access to initial diagnostic assessment for ASD or any developmental concern is poor in many regions, delaying time to diagnosis, and eventual treatment. In addition, not all children referred for possible ASD receive this as a final diagnosis. Our center redesigned our ASD/Developmental Concern diagnostic model for children under age 3 years, to improve access, and we also sought an improved understanding of the ultimate yield of ASD diagnosis for children under 3 referred for possible ASD or other developmental concern.

Objectives: (1) Determine diagnostic yield of arena assessments for children age 3 and under, referred for ASD or other developmental concerns; (2) Determine if ASD specific language in the referral modifies the likelihood of ASD diagnosis; (3) Assess average time to diagnosis.

Methods: Multidisciplinary arena assessment model for ASD or other developmental concern was tested and implemented (previously reported). Charts of 319 patients under 3 years of age (range 13-35 months), evaluated for ASD or other developmental concern between Jan. 2015 and May 2016 were reviewed for referral factors (referral reason, referring provider), and for final diagnostic determination. Time from referral to evaluation and final diagnosis were tracked as part of an ongoing Quality Improvement Initiative addressing access.

Results:  293 (91%) patients completed an evaluation for possible ASD or other developmental concern and were included in analysis. 116 patients (39.5%) received a final diagnosis of ASD, regardless of referral question. 189 patients (64.5%) had ASD specific language in their referral ("concern for autism", "MCHAT", "rule out autism"). Children with ASD specific referral language were more likely to have a final diagnosis of ASD compared to children without ASD referral language (46.6% vs. 26.9%; p=0.001).

Children not diagnosed with ASD received other developmental diagnoses, including global developmental delay (46.9%), language delay (23.2%), and behavior disorder (17.5%).

Average time from referral to evaluation was 20 days and time from referral to final diagnosis was 40 days.

Children referred who were age <24 months (n=226) were more likely to receive a diagnosis of ASD than those referred 24-36 months (42.5% vs. 29.9%)

Conclusions: Fewer than half of children referred for possible ASD received a final diagnosis of ASD, even when referral includes autism specific language. Children not receiving a diagnosis of ASD had other developmental concerns warranting intervention. Average time to final diagnosis was improved in our center through the development of a comprehensive arena assessment model, the addresses both possible ASD and other developmental concerns.