The ratio of boys to girls who qualify for an autism diagnosis drops to about 3-to-1 in a massive new analysis of published research1.
The findings highlight the need to look out for girls with autism who may be misdiagnosed, identified late or overlooked entirely.
Most sources put the sex ratio in autism at 4-to-1. The new analysis is based on data from 54 prevalence studies worldwide, with a total of nearly 14 million participants, including 53,712 children with autism. Overall, these studies show that there are 4.2 boys for every girl with autism.
But a lower ratio, 3.25 boys for every girl, emerges from studies in which researchers evaluate participants for autism, rather than interviewing parents or reviewing medical or school records.