Despite increased awareness of autism spectrum disorder (ASD) among both healthcare professionals and the general public, data indicate that the average age at diagnosis is older than 4. Routine screening in the primary care medical home has been promoted in an effort to enhance identification and diagnosis of children with ASD, so that they can access interventions at earlier ages. As it has not been previously demonstrated, my colleagues and I conducted a study to answer the question “Do higher rates of ASD screening lead to earlier ages of diagnosis?”

For a study published in Pediatrics, we examined referral patterns within a large network of primary care pediatric practices with high rates of ASD screening using the Modified Checklist for Autism in Toddlers (MCHAT) at both 18 and 24 month well-child visits. Patients with a failed ASD screen were then followed longitudinally for up to 4 years. Rates of referral (and referral completion) to an ASD specialist for diagnostic evaluation and to early intervention and therapeutic services were analyzed.

Among the 530 children who failed the MCHAT, less than one-third were referred to a specialist for diagnostic evaluation. Children who were referred at the time of failed screening were diagnosed an average 16 months earlier than children who were referred later.

Our study demonstrates that increased rates of screening for ASD do not guarantee earlier age of diagnosis; instead, the primary care pediatrician’s actions following a failed screen are of most importance. Given the long wait time for an evaluation with an ASD specialist, education for all pediatricians (both in primary care practice and training) in the diagnostic evaluation of ASD should be a priority. Pediatricians should be empowered to independently diagnose children within the medical home who meet criteria for ASD. When there is uncertainty, referral for further evaluation with an ASD specialist and monitoring that referrals are actually completed are crucial to ensure that a diagnosis is made. Further research into perceived barriers to referral by pediatricians following a failed ASD screen and perceived barriers to completion of referrals by families will help support the effort for earlier diagnosis and access to interventions for children with ASD.