Global prevalence of autism: A systematic review update.
Level 1 - systematic review of randomized trials
Systematic review of prevalence studies (graded by design analogy)
PubMed 35238171 · doi:10.1002/aur.2696
What was done
Authors conducted a systematic review updating their 2012 review, searching MEDLINE through November 2021 for studies estimating the prevalence of autism worldwide. Two independent researchers extracted data on prevalence figures, biological sex, sociodemographic status, ethnicity/race, and co-occurring intellectual disability.
What was found
Across 71 studies published since 2012 reporting 99 estimates, the median reported prevalence of autism was 100/10,000 (1.00%), with a range of 1.09/10,000 to 436.0/10,000. The median male-to-female ratio was 4.2. A median of 33.0% of autism cases had co-occurring intellectual disability.
Why it matters
This update provides a global benchmark estimate of autism prevalence (approximately 1 in 100) and documents how increases over time reflect evolving case definitions, improved screening capacity, and rising community awareness.
Limits
The review did not include a formal quality appraisal of included studies due to wide methodological differences. Wide variations in diagnostic criteria, case-finding methods, and regional health service capacities substantially limit direct comparisons across studies and geographies.
Cited by
- context Autism prevalence in children has increased from 1 in 10,000 to approximately 1 in 130 over recent decades.