Which population groups are at risk and why?
This section will focus on core epidemiological issues that take account of fixed risk factors (such as age, gender, ethnicity, family history) and modifiable risk factors (such as behaviour). The wider determinants of health (such as housing, transport and environment) are also considered.
Gender
Traditionally, ASD is more commonly diagnosed in males than females with current gender ratios at 3:1 (males: females)5.
However, current diagnostic criteria are often based on male presentations leading to missed or delayed diagnoses in females6.
Socioeconomic status
Socioeconomic status influences autism diagnosis but not prevalence. The National Autistic Society (UCL Study) found that there is significant underdiagnosis in areas of higher deprivation, especially among adults aged 20-49 and over 507.
Qualifications
A 2024 report from NIHR ARC North East and North Cumbria found children born to mothers without educational qualifications were diagnosed with autism two years later than their peers8.
Ethnicity
Data from the School Census from the National Pupil Database found that among individuals aged 2-21 years old in state-funded schools in England, prevalence was highest in pupils of black ethnicity. This is followed by Mixed and White ethnic groups9.
Vulnerable Children
Children in Care (Looked-after Children) are significantly more likely to be diagnosed with neurodevelopmental conditions including ASD. Up to 12% of children in care met criteria for ASD (2021) whereas general population prevalence was 1-2%10.