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Prevalence and Characteristics of Autism Spectrum Disorder Among 4-Year Old Children in the Autism and Developmental Disabilities Monitoring Network
Journal of Developmental and Behavioral Pediatrics

On-line: December 9, 2015

Relatively little is known about the expression and prevalence of Autism Spectrum Disorder (ASD) among preschool-aged children.  Investigators from Rutgers—New Jersey Medical School participated in the first multi-state epidemiologic study of ASD among 4-year olds.   The goals were to determine baseline ASD prevalence rates, describe the characteristics of these children and identify any disparities in identification or intervention.   The study encompassed 58,000 children living in Arizona, Missouri, New Jersey and Utah.  ASD prevalence estimates were established according to an active, multiple-source method, based on extensive review and comprehensive analysis of information contained in health and education records.  

The New Jersey arm of the study was conducted in Essex and Union counties and focused on 17,866 children, born in 2006.  The surveillance area is diverse (33%-white, 33%-black, 29%-Hispanic, 5%-Other) and includes the full-range of socioeconomic strata.   All school districts in the region participated, as did the major clinical centers and Early Intervention Programs.  Over 2,100 children’s records were reviewed and analyzed.  Even at age 4, the amount and quality of information from available records was high.  

In the multi-state Early Autism and Developmental Disorders Monitoring (Early-ADDM) Network, ASD prevalence ranged from 8.5 to 19.7 per 1,000.   The New Jersey ASD estimate --19.7 per 1,000 was significantly higher than from other Network states.   Eighty-six percent of (New Jersey) identified ASD preschoolers satisfied the criteria for Autistic Disorder and 20% had indication of regressive ASD.  Boys out-numbered girls with ASD four-fold, but girls with ASD were more likely to have a professional evaluation before 36-months.   While the investigators did not observe a significant race/ethnicity-based difference in ASD prevalence, white children were more likely have a professional evaluation before 36-months than black and Hispanic children.  Compared to the other Network states, New Jersey children had earlier first professional evaluations and were more likely to be evaluated before 36-months.  Significant proportions of New Jersey 4-year olds with ASD received Early Intervention Program (EIP) (60%) and Preschool Child with a Disability (90%) services. 

What is this report telling us?
For the first time, a coordinated and comprehensive multi-state effort to estimate ASD prevalence in preschool-age children was conducted and yielded higher-than expected rates.  The study findings suggest that as many as 2% of preschool-age children have an ASD and that minority children with ASD are less likely to receive a professional evaluation before 36-months.

Why is the New Jersey 4-year old ASD estimate higher than in all other Early-ADDM states
The ASD prevalence rate among preschool-age children is significantly higher in New Jersey than in other states, largely because of excellent access to records and more-detailed information available in New Jersey, leading to more complete estimation of ASD.   For example, Missouri and Wisconsin could only review clinical records, leading them to ASD (under) estimates of 8.5 and 8.8 per 1,000. 

Is the 4-year old rate described by the study an accurate estimate of total ASD prevalence?
While they are robust in comparison to previous studies of ASD in preschool-age children, the 4-year old ASD rates reported by this study underestimate the total prevalence of ASD in the study communities.  Some children with ASD, especially those with lesser disability, do not come to the attention of health or education providers, until after age 5.   Surveillance of this group for 2014, when the cohort was 8-years old, is ongoing and will show the difference between preschool-age and peak ASD prevalence, thereby allowing researchers to anticipate or predict future peak prevalence from younger (age 4-years) cohorts.  

What is next for ASD studies in New Jersey?
The New Jersey Autism Study researchers are currently conducting 2014 (peak: 8-year old) surveillance activities in Essex, Hudson, Union and Ocean counties and monitoring ASD in 4-year olds (2010 birth cohort) residing in Essex and Union counties.  

This study was made possible by support from the Centers for Disease Control and Prevention (CDC) to investigators in Arizona, Missouri, Utah, Wisconsin and New Jersey. The New Jersey investigators conducted the study with the cooperation of the New Jersey Departments of Health and Education, participating school districts and clinical (developmental health) providers in the region. 

For additional information, please visit the New Jersey Autism Study website: or contact
Walter Zahorodny, PhD, the Principal Investigator, or




IMFAR is one of the more prominent scientific symposiums in autism research, allowing scientists from every corner of the world to share and learn about the latest research in ASD.

NJAS investigators submitted three abstracts in November 2011 for IMFAR 2012 Conference. All three abstracts were accepted for poster presentations!


Title: Autistic Characteristics Before and After the Age of Three in Children with Autism Spectrum Disorder

Authors: Josephine Shenouda, MS, Stephanie Neves, MAT, Walter Zahorodny, PhD
Date & Time: Thursday, May 17, 2012, 1:30 PM - 5:30 PM
Location: Sheraton Hall, Sheraton Centre

Title: Intellectual Ability and Autism

Authors: Stephanie Neves, MAT, Josephine Shenouda, MS, Harsh Patel, BA, Walter Zahorodny, PhD
Date & Time: Friday, May 18, 2012, 1:30 PM - 5:30 PM
Location: Sheraton Hall, Sheraton Centre

Title: Autism Spectrum Disorders & Regression: Findings from a Population Based Study

Authors: Harsh Patel, BA, Josephine Shenouda, MS, Walter Zahorodny, PhD
Date & Time: Thursday, May 17, 2012, 1:30 PM - 5:30 PM
Location: Sheraton Hall, Sheraton Centre

For more information please contact Josephine Shenouda, or (973)972-9773.