Prevalence of autism spectrum disorders in Hispanic and non-Hispanic white children.

Overview

abstract

OBJECTIVE: The number of individuals diagnosed with autism spectrum disorders (ASDs) continues to increase in the United States and other developed countries; however, ASD is diagnosed less commonly in Hispanic than in non-Hispanic white individuals. This report analyzes differences in ASD prevalence between Hispanic and non-Hispanic whites in a large, population-based sample of 8-year-old children, and explores how prevalence has changed over time. METHODS: Population-based surveillance of ASD was conducted on 142 717 8-year-old children. Evaluation of clinical and educational records resulted in 1212 children meeting the case definition criteria in 4 study years between 2000 and 2006. RESULTS: ASD prevalence in Hispanic children was lower than in non-Hispanic white children (P < .005) for all study years. More Hispanic than non-Hispanic white children met the case definition for intellectual disability (P < .05) in study years 2004 and 2006. Prevalence of ASD diagnosis increased in both groups; the Hispanic prevalence almost tripled, from 2.7 per 1000 in 2000 to 7.9 per 1000 in 2006. A comparison of prevalence ratios found that Hispanic and non-Hispanic white ASD prevalence became significantly more similar from 2000 to 2006 (χ(2) = 124.89, P < .001). CONCLUSIONS: The ASD prevalence for Hispanic individuals in this population-based sample is substantially higher than previously reported. Nonetheless, Hispanic children continue to have a significantly lower ASD prevalence in comparison with non-Hispanic whites. The prevalence of ASD is increasing in both populations, and results indicate that the gap in prevalence between groups is decreasing.