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The Rapid Interactive Autism Screening Test in Toddlers: Further Validation and Generalization
Objectives: To generalize and evaluate the effectiveness of the RITA-T, a new level 2 screening assessment for ASD in diverse populations. This study is further designed to determine the optimal cut-off score for use in screening ASD and thus improve referrals to tertiary care centers.
Methods: The RITA-T consists of nine activities that evaluate the participant’s social, communication, and interaction skills. Use of language and verbal commands is limited to simple phrases intended to direct the participant’s attention and does not rely on the participant’s need to interpret complex commands that may be limited by vocabulary.
Four Early Intervention (EI) providers from the THOM EI program in Worcester, MA were trained on the RITA-T. The test was administered to 81 toddlers from diverse ethnic and racial backgrounds. From this group, 70 toddlers had a positive MCHAT-R (Modified Checklist for Autism in Toddlers- Revised) or other behavioral concerns for ASD. After screening with the RITA-T, toddlers were then referred to a diagnostic team that administered the Autism Diagnostic Observation Schedule-2 (ADOS-2) and the Mullen Scales of Early Learning (MSEL). A final clinical diagnosis was made as ASD or non-ASD based on testing and clinical presentation. Eleven toddlers were referred by EI after being evaluated as low risk of ASD. Clinical diagnosis was made based on the results of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) , MCHAT-R, and Batelle Developmental Inventory. Each participant’s RITA-T score was compared to their final clinical diagnosis and ADOS-2 diagnosis to evaluate the validity of the RITA-T and determine the optimal cut-off score.
Results: Eighty-one toddlers (78% male) were evaluated. The age of the participants ranged from 18 to 35 months (mean age 27.3 months). The study population was 58% white, 20% Hispanic, 15% African-American, and 7% Asian. Of those, 57 (70.4%) were diagnosed with ASD and 24 (29.6%) were diagnosed as non-ASD. Optimal cutoff score for the RITA-T was determined to be 12(PPV = 0.93, NPV = 0.95). Those with a score lower than 12 were considered low risk for ASD. Patients with a score from 12 to 16 were considered to be intermediate risk requiring further evaluation, whereas those with scores higher than 16 were most likely high risk for ASD.
Conclusions: Training and administration of the RITA-T is generalizable, and results support its validity and correlation with clinical diagnoses. Cut-off score was further refined. Further testing will evaluate the effectiveness of the RITA-T screening in those 12- 18 months.