Early Diagnosis of Autism Spectrum Disorder Via a Transdisciplinary Clinic

Background:  

Currently, there are multiple barriers during the diagnosis and treatment of Autism Spectrum Disorders (ASD). These barriers include prompt referrals from primary care providers to specialists, long waitlists for diagnostic services, and subsequent intervention (Filipek, et al., 1999). As early diagnosis and intervention for ASD are crucial for positive outcomes (Bryson, Rogers, and Fombonne, 2003), alternative diagnostic methods should be explored. One possible alternative method, the Medical Diagnostic Clinic is a transdisciplinary diagnostic clinic, where children birth to age three are evaluated to assess whether there is a medical reason for their delays.  The arena-style evaluation is typically a multidisciplinary team, including a physician, a clinical psychologist, a speech and language pathologist, an occupational therapist, and a developmental therapist all of whom have strong backgrounds in diagnosing and treating children with developmental disabilities (Klin, et al., 2005). Though this approach appears promising, little systematic research has been conducted to determine the reliability and accuracy of ASD diagnoses by a transdisciplinary clinic.

Objectives:

To examine the validity and reliability of an ASD diagnosis before the age of three within a transdisciplinary clinic.  The study re-assessed 34 children who were evaluated prior to age three by a transdisciplinary team, 20 with autism spectrum disorder and 14 who did not meet criteria during their initial assessment. The Autism Diagnostic Observation Schedule (ADOS; Lord, et al., 2000) and Autism Diagnostics Interview-Revised (ADI-R; Le Counteur et al., 2003) were completed at follow-up.  The stability of the diagnosis was examined by comparing the original diagnosis given by the transdiciplinary team and that of the follow up evaluation.

Methods:  

34 participants were evaluated by a transdiciplinary clinic with an age range of 13 – 36 months.  The same children were re-evaluated after the age of 3, with an average age of 49.35 months. Either the Screening Tool for Autism in Two Year Olds (STAT; Stone & Ousley, 1997) or the Childhood Autism Rating Scale (CARS; Schopler, Reichl, & Renner, 1998) were administered during the transdisciplinary evaluation. Children were then randomly selected from a database and assigned to the ADI-R and ADOS evaluator, who was blind to diagnosis of the child. The diagnoses from the two time points were compared to determine the accuracy and reliability of the diagnosis assigned by the transdisciplinary clinic prior to the age of three.

Results:  

Diagnostic accuracy of the transdisciplinary clinic was high compared to the ADOS/ADI-R. Specifically, inter-rater reliability of diagnosis was found to be 82.35% with a Kappa coefficient of .62 between initial diagnosis and follow up.

Conclusions:  

Findings of the current study suggest that the transdisciplinary clinic approach is a reliable and valid method of identifying children at risk for ASD prior to the age of 3. This appears to be highly accurate in the identification of ASD in the birth to three population, which may enhance service delivery and developmental outcomes for these youngsters.  Transdisciplinary teams could serve as a way of getting children and families connected with targeted intervention while they wait for a formal diagnostic evaluation.