Early Diagnosis of ASD in Toddlers: Models to Improve Access and Wait Times

Background:  Early and intensive intervention can improve outcomes in ASD. Currently in the US, early diagnosis of ASD and access to services are delayed by long wait times. We report and discuss the results of successful ASD Assessment Processes in two different diagnostic and tertiary centers; both use a two-level ASD screening model and evaluation algorithm using the RITA-T (Rapid Interactive Screening for Autism in Toddlers) for toddlers under 39 months of age

Objectives:  Improve early detection of autism with a two level screening test using the MCHAT R/F as a Level 1 and the RITA-T as an interactive Level 2 screening test, in two different diagnostic centers.

Methods:  This two screening model was piloted in two different centers: a) In Calgary, with a waitlist >12 months for children under 39 months of age, a Quality Improvement Project was commenced in 2013 aimed at creating an efficient, sustainable and evidence-based ASD diagnostic process. Toddlers were initially screened by the MCHAT and the RITA-T. Three groups were created (low, moderate and high risk) depending on RITA-T and MCHAT scores. Diagnostic evaluation was completed on each group. b) In Worcester, MA, this process tested the two-level screening model completed by Early Intervention (EI) providers, and linking EI and diagnostic center for improved early screening, identification, communication and wait times. Early Intervention providers in the largest program in the Worcester area were trained with the RITA-T and on the MCHAT R/F. They screened all their toddlers already enrolled with the MCHAT and completed the RITA-T on those with a positive score and on a sample of 20 toddlers with an initial positive MCHAT but a final negative result. Toddlers were then referred for diagnostic evaluation.

Results: A) In the Calgary Group: wait improved (<28 days), evaluation processes streamlined, and validation of this process was confirmed by parents. A total of 176 toddlers were evaluated with this model. The statistical and descriptive data of the RITA-T in this model are currently being analyzed. b)-In Worcester, the study is ongoing currently; so far 90 toddlers were evaluated. Of those 75 had an ASD diagnosis. The RITA-T preliminary properties in this setting show sensitivity 0.9 and specificity of 0.85 and a positive predictive value of 0.9. Early Intervention providers relate improved communication with diagnosticians and better early detection skills and wait time to be seen is within 2 months Conclusions:  A two level ASD screening model that integrates the MCHAT R/F and the RITA-T improves early detection, wait times and communication in tertiary and diagnostic centers and improves communication between Early Intervention providers and diagnosticians.