Follow up of children with autism spectrum disorders: stability and change in diagnosis.

OBJECTIVE: To assess diagnostic stability of initial autism spectrum disorder (ASD) diagnosed in children three years or less.
METHODS: Participants in the study included 77 (64 boys,13 girls) children in whom a diagnosis of Autistic Disorder (AD) and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) was made at age 3 years or less as per the DSM IV criteria. Children were recruited from the Outpatient services of the department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh. Multi-disciplinary evaluations including neurological, diagnostic, cognitive, and behavioral assessments were made. In addition, the Childhood Autism Rating Scale (CARS) was administered to assess symptom severity. Follow up was done around 4 years of age.
RESULTS: At Time 1, 64 (83.11%) children were diagnosed as AD and 13 (16.88%) children with PDD-NOS. Follow up was possible in only 43 children (55.8%) at the mean age of 4 years 1 month (SD = 0.99) after a mean age interval of 1.65 years (SD = 0.95). At Time 2, 37 (86%) children were diagnosed as AD and 4 (9.3%) children were diagnosed with PDD-NOS, and 2 (4.65%) children were found to be off the ASD spectrum. The diagnosis of ASD (AD and PDD-NOS) was stable over time and 41 (95.3%) out of 43 children retained an ASD diagnosis. Looking at specific ASD diagnosis, AD diagnosis was stable for 33 out of 37 (89.18%) children and the PDD-NOS was stable for only 1 out of 6 (16.67%) children.
CONCLUSIONS: An early and a stable diagnosis of ASD is possible provided there are expert clinicians available. Early detection and diagnosis of ASDs allows opportunities for children to profit more from early supports and interventions.