A Diverse Autism Registry for Etiologic and Effectiveness Studies: Prevalence and Demographic Characteristics

Background: While the numbers of individuals with Autism Spectrum Disorders (ASD) continues to grow and new interventions and treatments are introduced, effectiveness studies of autism treatments remain sparse.  The major limitations to conducting such studies include locating, characterizing, and enrolling sufficiently large and representative ASD patient samples. 

Objectives: To create a large, comprehensive and dynamic ASD registry across several integrated health systems participating in the NIMH Mental Health Research Network (MHRN). This registry will enable rapid identification and enrollment of patients into future large-scale comparative effectiveness studies testing treatment and preventive and services interventions, as well as future pharmacogenomic and etiologic investigations. 

Methods: The MHRN includes nine public-domain research centers based in integrated not-for-profit HMOs.  Combined, the MHRN serves a diverse patient population of 10 million people in 11 different states. The ASD registry is based in five of the nine participating MHRN sites: Kaiser Permanente (KP) Northern California, KP Southern California, KP Northwest, KP Georgia, and Harvard Pilgrim Health Plan.  ASD registry investigators have developed case-finding algorithms in order to identify children with ASD from electronic medical records and health claims data.  ASD diagnoses are validated using structured record review followed by expert review.  Diagnostic and demographic data recorded in health plan electronic databases from 1995-2010 on all 0-17 year olds who were health plan members as of December 2010 were used to calculate preliminary estimates of ASD prevalence across all 5 participating sites.

Results: Among the 2,049,442 pediatric patients receiving health care at one of the five participating sites as of December 2010, 23,811 children with an ASD diagnosis were identified.  The overall prevalence of ASD was 1.2%, and ranged from 0.86% to 1.6% across the five sites. As of December 2010, most ASD cases were 10-14 years old (36% across all sites, range: 35%-41%) or 5-9 (35% across all sites, range: 30%-36%). Fewer cases were seen in the 15-17 age group (18%, range: 16%- 22%) and the 0-4 age group (11%, range: 7%-12%). The ratio of male to female cases was 4.29 across all sites (range:  3.71-5.11). The majority of children diagnosed with an ASD were diagnosed with Autistic Disorder (n=14,061, 59% across all sites, range: 33%-71%).

Conclusions: Diversity of member demographics, insurance coverage, and organization of health services make this registry an ideal environment for studying variation in care, comparing effectiveness and cost of treatments across practice environments, and studying dissemination of information and health policies related to autism. Future aims include conducting web-based surveys of the parents of children affected by ASDs to identify use of services not provided by HMOs. Additional aims include collection of genetic material from individuals with ASD’s and from family members, and harmonization of data from birth certificates, census information, standardized ASD assessment protocols, claims data, and EMR data.