Abstract
Clinical initiatives have aimed to reduce the age at ASD diagnosis in the UK. This study investigated whether the median age at diagnosis in childhood has reduced in recent years, and identified the factors associated with earlier diagnosis in the UK. Data on 2134 children with ASD came from two large family databases. Results showed that the age of ASD diagnosis has not decreased. The median age of diagnosis of all ASDs was 55 months. Factors associated with earlier age of diagnosis were autism diagnosis (compared with other ASD), language regression, language delay, lower socioeconomic status, and greater degree of support required. Effective clinical strategies are needed to identify children with characteristics that have in the past delayed ASD diagnosis.