At least 1% of children in Ireland have autism, which is similar to rates in the UK and US, a new study has shown.

Autism, also known as autism spectrum disorder (ASD), is a biological disorder of the brain that impairs communication and social skills. Signs can include an absence of eye contact, apparent aloofness, avoidance of physical contact even with family and difficulty dealing with interruptions to routine.

Until now, it has been unclear how often the condition occurs in Ireland, so researchers at the DCU School of Nursing and Human Sciences decided to look into this.

"Determining the prevalence of ASD is important for burden of diseases analysis and policy-making decisions. The prevalence of ASD among school going-children has not previously been explored in the Republic of Ireland," they noted.

They provided almost 8,000 parents in Cork, Waterford and Galway with ASD screening questionnaires. The parents filled out the questionnaires on behalf of their children, all of whom were in primary school.

The researchers found an overall prevalence rate of 1% among children.

Within special education schools, the estimated prevalence rate of autism was 52%. However, the researchers pointed out that the response rate from parents with children in special education schools was poor, therefore ‘it is difficult to make an accurate estimation of ASD prevalence from this sample'.

According to the study, the 1% prevalence rate ‘should be regarded as a minimum prevalence rate'. This is because while the overall response rate for children in national schools was high, ‘a significant number of children identified and invited to attend multidisciplinary assessment did not avail of the assessment or were lost to follow up'.

"The process of screening and diagnosing autism spectrum disorders is complex, requiring input from multiple social, educational, medical and psychological services. Standardising the diagnosis process across all these stakeholders will allow us to better determine prevalence rates across the country and correspondingly deliver more effective policy responses to autism spectrum disorders," commented one of the principal investigators, Dr Mary Rose Sweeney.

The DCU team called for the continued monitoring of ASD prevalence rates in Ireland, and for the creation of a register for all children who are diagnosed with the condition. It also called for an economic evaluation of the costs and benefits of ASD intervention.

The study, Autism Counts, was funded by Irish Autism Action.