How Early Do Parent Concerns about Development Predict Later Autism Diagnosis?

Background: Recently published guidelines from the American Academy of Pediatrics (AAP) recommend that pediatricians routinely ask parents about developmental concerns and screen all children for autism twice by the 2^nd birthday. Parent concerns, along with other risks, can trigger a referral for specialized evaluation. Most previous studies have used retrospective parent report to examine how well early concerns predict later outcomes, but these can be biased by knowledge of the child’s eventual diagnosis, poor recall, or lack of sensitivity to developmental differences. 

Objectives: This study collected parent concerns about development for infants at high (n=136) and low risk (n=83) for autism, using a prospective longitudinal design, to see whether they were predictive of later autism diagnosis.

Methods: Parents were asked at intake and when their infant was 6, 12, and 18 months of age: “Do you have any concerns about [x’s] development or behavior at this time?” Responses were recorded verbatim and coded by raters unaware of group membership. Concerns were grouped into two categories: ASD Concerns (specific concerns about social or communication development or repetitive behaviors, or general worries about recurrence of autism) and General Concerns (medical, regulatory, cognitive, behavior or other concerns). Participants were followed to 36 months of age, when they were classified into one of four outcome groups: Autism/ASD (n = 24), Other Clinical Outcomes (e.g., global developmental delays, speech-language delays, behavior problems; n = 45), High Risk Typical (no clinical diagnosis and had an older sibling with autism, n = 79), and Low Risk Typical (no clinical diagnosis and had older siblings without autism, n = 70).

Results: At intake, there were no differences in General Concerns between infants with and without an older sibling with autism, but there were significant differences in ASD Concerns (Wald X² = 7.49, p < .01; 19% high risk v. 1% low risk group). Change in rate of ASD Concerns from 6 to 18 months was also significantly related to outcome. Parents of the Autism/ASD outcome group had significantly more General Concerns across all ages (Wald X² = 12.99, df = 1, p < .001) and significantly more ASD Concerns at 12 and 18 months of age, as well as a steeper growth rate in number of concerns (Wald X² = 9.55, p < .01). 

Conclusions: Not surprisingly, parents who already have a child with autism have more concerns about development of younger siblings than parents without a child with autism. At 6 months of age, these concerns do not predict which infants will go on to develop autism. By 12 and 18 months, however, parents of infants who are later diagnosed with autism have significantly more concerns, particularly in the areas of social and communication development, than parents of children with typical or non-autistic clinical outcomes. These results suggest that parent concerns about early development are good indicators of developmental problems and that the AAP guidelines to elicit and act upon parent concerns are valid.