PS1-13: Variation in the Incidence and Prevalence of Autism from Multiple Health Systems: Findings from the Mental Health Research Network Autism Registry Study.
Autism spectrum disorders (ASD) are characterized by impairments in social interaction and communication, as well as restricted, stereotyped interests and behaviors.
A recent study found that approximately 1 in 88 children in the U.S. were diagnosed with an ASD and that prevalence varied widely among different demographic groups.
The goals of this study were to obtain accurate prevalence and incidence statistics for ASD across several large, diverse health systems and to describe the variation of these statistics across demographic factors.
All members within the five participating health systems born between January 1, 1993 and December 31, 2008 with electronic claims, enrollment, or medical record information were included in the study. Information on member demographics and ASD subtypes were collected from earliest available records at each site through the end of December 31, 2010. Individuals with an ASD diagnosis from an ASD specialist or two or more ASD diagnoses from non-specialists were defined as valid cases.
A preliminary examination of data from one site (N = 1,271,823) found 10,114 individuals <18 years ever diagnosed with an ASD.
Of those 10,114 ASD cases, 8,085 met the validation criteria and were included in final analyses.
Prevalence of all ASDs in children ≤8 years old was 1.1/1000 in 2001 (1 in 909 children) and increased steadily to 7.1/1000 in 2010 (1 in 141 children).
Prevalence specifically for autistic disorder (AD), a more severe subtype, in children ≤8 years old was 0.3/1000 in 2001 and increased to 1.9/1000 in 2010.
Similar secular increases were noted for incidence.
Prevalence and incidence varied greatly among demographic groups.
Prevalence of all ASDs in 2010 was
8.4/1000 among Whites,
7.1/1000 among Blacks, and
10.6/1000 among Asians.
Prevalence of ASDs among females was lower than among males in all years (2010 males: 11.2/1000, 2010 females: 2.8/1000).
This study provides up-to-date prevalence and incidence information from a group of large, diverse, community-based settings. Incidence and prevalence differed across racial groups and sex status. Strong increasing trends in the diagnosis of ASDs in general, as well as the AD subtype, were observed.