Developmental disabilities affect about 17% of children under age 18 years in the U.S.  The Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) monitors rates of mental retardation, cerebral palsy, hearing loss, and vision impairment among children aged 8 years in a five-county area.  MADDSP gathers population-based data from multiple sources every two years, and it provides a model for 16 other states that conduct surveillance. This report compares rates from the years of 2000 and 1996.

Cases were identified from designated educational and clinical sources.  These included public school systems (9) and developmental disabilities programs affiliated with the state Department of Education as well as clinical facilities for children with developmental disabilities, children’s hospitals and associated clinics, diagnostic and evaluation centers, and certain private clinicians.  In 2000, over half (53%) of the cases were identified from school sources only, whereas 41% were identified in both school and clinical sources. 

In 1996, the prevalence of mental retardation was 15.5 per 1,000 children; in 2000, the rate was 12.0 per 1,000.  The prevalence of cerebral palsy was 3.6 per 1,000 in 1996, and 3.1 per 1,000 in 2000.  The rates of mental retardation and of cerebral palsy were higher among males and black children.  The rates of hearing loss were 1.4 per 1,000 in 1996 and 1.2 per 1,000 in 2000.  The rates of vision impairment were also 1.4 per 1,000 in 1996 and 1.2 per 1,000 in 2000.  There were no significant differences by year across disabilities when gender, race, and severity were considered.

During 1996 and 2000, 9.4% and 11.0% of this population had two disabilities, respectively.  In 2000, the percentage with three disabilities was 3.4%.
MADDSP data are used to monitor the US Healthy People 2010 targets for the prevention of mental retardation and cerebral palsy.  These data can help identify risk factors for developmental disabilities.  One of the impacts of MADDSP impacts was newborn hearing screening.

(Bhasin TK, et al. MMW 2006;55(SS01):1-9)

Comment: Earlier studies found that, by age 8 years, most children with a developmental disability have been enrolled in a special education program and identified by service providers.  The finding that nearly half of the children were not identified in health care reports may indicate limited access to developmentally-oriented exams or limited  documentation in healthcare records.      --J.O.