Prevalence of autism spectrum disorders in a total population sample

Young Shin Kim, Bennett L. Leventhal, Yun Joo Koh, Eric Fombonne, Eugene Laska, Eun Chung Lim, Keun Ah Cheon, Soo Jeong Kim, Young Key Kim, Hyun Kyung Lee, Dong Ho Song, Roy Richard Grinker

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Abstract

Objective: Experts disagree about the causes and significance of the recent increases in the prevalence of autism spectrum disorders (ASDs). Limited data on population base rates contribute to this uncertainty. Using a population-based sample, the authors sought to estimate the prevalence and describe the clinical characteristics of ASDs in school-age children. Method: The target population was all 7- to 12-year-old children (N=55,266) in a South Korean community; the study used a high-probability group from special education schools and a disability registry and a low-probability, general-population sample from regular schools. To identify cases, the authors used the Autism Spectrum Screening Questionnaire for systematic, multi-informant screening. Parents of children who screened positive were offered comprehensive assessments using standardized diagnostic procedures. Results: The prevalence of ASDs was estimated to be 2.64% (95% CI=1.91-3.37), with 1.89% (95% CI=1.43-2.36) in the general-population sample and 0.75% (95% CI=0.58-0.93) in the high-probability group. ASD characteristics differed between the two groups: the male-tofemale ratios were 2.5:1 and 5.1:1 in the general population sample and highprobability group, respectively, and the ratios of autistic disorders to other ASD subtypes were 1:2.6 and 2.6:1, respectively; 12% in the general-population sample had superior IQs, compared with 7% in the high-probability group; and 16% in the general-population sample had intellectual disability, compared with 59% in the high-probability group. Conclusions: Two-thirds of ASD cases in the overall sample were in the mainstream school population, undiagnosed and untreated. These findings suggest that rigorous screening and comprehensive population coverage are necessary to produce more accurate ASD prevalence estimates and underscore the need for better detection, assessment, and services.

Original languageEnglish (US)
Pages (from-to)904-912
Number of pages9
JournalAmerican Journal of Psychiatry
Volume168
Issue number9
DOIs
StatePublished - Sep 1 2011

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ASJC Scopus subject areas

  • Psychiatry and Mental health

Cite this

Kim, Y. S., Leventhal, B. L., Koh, Y. J., Fombonne, E., Laska, E., Lim, E. C., Cheon, K. A., Kim, S. J., Kim, Y. K., Lee, H. K., Song, D. H., & Grinker, R. R. (2011). Prevalence of autism spectrum disorders in a total population sample. American Journal of Psychiatry, 168(9), 904-912. https://doi.org/10.1176/appi.ajp.2011.10101532