Age At ASD Diagnosis in the UK Has Not Reduced Over Recent Years: Evidence From a Large ASD Research Database

Background:  Early diagnosis of ASD is desirable to help parents understand their child’s neurodevelopment, give parents appropriate management advice as early as possible, and commence intervention strategies that may improve children’s developmental progress. In recent years, clinical initiatives and publicity about ASD have improved UK ASD diagnostic services. However, to date, systematically collected recent UK data about the age at diagnosis of children with ASD have been lacking.

Objectives:  1. To identify whether age at ASD diagnosis has changed over recent years in the UK. 2. To explore the phenotypic factors associated with earlier diagnosis.

Methods:  Data were available from the Autism Spectrum Database-UK (ASD-UK). ASD-UK is a research database to which families of children with ASD are recruited by more than fifty multidisciplinary UK child health teams. Data are collected about each child, and families can be contacted about UK ASD research projects. Analysis of gender, ASD characteristics, learning disability, and social deprivation scores has already shown that ASD-UK children are broadly representative of children with ASD in the UK (Warnell et al., in preparation).

Results:  Data from 548 children with ASD aged 2-16 years were available (male:female ratio of 4:1). Three quarters of the ASD-UK children were diagnosed between 2007-2012. For those years, children’s median ages at diagnosis were: 2007, 53 months; 2008, 48 months; 2009, 58 months; 2010, 52 months; 2011, 61 months; 2012, 61 months. Considering all ASD-UK children, 58% were diagnosed before age 5 years; one quarter of children received their diagnosis before age 3 years. Overall, the age at diagnosis of girls and boys was very similar. Controlling for language ability, SCQ scores were similar for children diagnosed before, and children diagnosed after 5 years (60 months). Children with a clinical diagnosis of ‘autism’ were more likely to be diagnosed earlier than children with ‘ASD’ or Asperger syndrome (Autism median age at diagnosis 42 months; ASD median 49.5 months; Asperger syndrome median 90 months).

Conclusions:  In the UK, the median age at ASD diagnosis remains around age 5 years; many children received a later diagnosis. An ‘Autism’ diagnosis was associated with an earlier age at diagnosis, but gender and a number of other aspects of the ASD phenotype were not. These data have implications for both parents and clinical services, regarding advice and support for families, and access to early intervention.