Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP)

Background

CDC began tracking the prevalence of intellectual disability, cerebral palsy, hearing loss, vision impairment, and epilepsy among children 10 years of age in 1984 as part of the Metropolitan Atlanta Developmental Disabilities Study. The success of that study prompted CDC to establish MADDSP in 1991 in order to estimate the number of children in the metropolitan Atlanta area who had one or more of four developmental disabilities—cerebral palsy, hearing loss, intellectual disability, and vision impairment. Autism spectrum disorder (ASD) was added to the program in 1996. MADDSP served as the model for the creation of the Autism and Developmental Disabilities Monitoring (ADDM) Network and, since 2000, has participated as one of the sites in the ADDM Network.

The goals of MADDSP are to

• Provide data about how common the selected developmental disabilities are among children in metropolitan Atlanta.
• Describe the characteristics of children with one or more developmental disabilities and how these characteristics may change over time.
• Assess possible relationships between birth characteristics, such as low birthweight and premature delivery, and the occurrence of developmental disabilities.
• Provide a framework for initiating special studies.

Methods

MADDSP was established in 1991 to estimate the number of children who had one or more of four developmental disabilities—intellectual disability, cerebral palsy, hearing loss, and vision impairment—in metropolitan Atlanta. Prevalence estimates are made every two years.

In 1996, ASD was added as a fifth developmental disability. All five disabilities were tracked by MADDSP until 2012. In 2014 and 2016, conditions were limited to ASD, intellectual disability and cerebral palsy; in 2018 and 2020, only ASD was included.

Until 1998, disabilities were tracked among children aged 3–10 years. From 2000 to 2016, disabilities were tracked among 8-year-old children. Since 2018, MADDSP has included 4-year-olds, 8-year-olds, and follow-up of 16-year-olds (whose records were previously included in MADDSP when they were 8 years old). From 1991 to 2014, the MADDSP surveillance area included five counties: Clayton, Cobb, DeKalb, Fulton, and Gwinnett. In 2016, MADDSP included DeKalb and Gwinnett counties. In 2018, MADDSP included DeKalb and Gwinnett counties (for 4-year-olds and 8-year-olds) and Fulton County (for 16- year-olds). In 2020, MADDSP included DeKalb County (4-year-olds and 8-year-olds) and Fulton County (4-year-olds, 8-year-olds, and 16-year-olds).

MADDSP identifies children through a process known as active record review. In this process, records are reviewed every other year for children who are the appropriate age within the year of interest and live with a parent or guardian who is a resident of one of the counties included in surveillance. Trained abstractorsA review records and abstract detailed information at multiple health and education sources (such as clinics and schools) in metropolitan Atlanta that evaluate and provide services to children with developmental disabilities. Until 2016, this information was then reviewed by trained clinicians who determined whether the child meets criteria for one or more of the developmental disabilities. Since 2018, clinician review is no longer performed.

MADDSP Criteria and Definitions

MADDSP includes children with the following characteristics:

• Who are the appropriate age (4, 8, or 16 years) during the year of interest
• Whose parent(s) or legal guardian(s) live in one of the selected counties in metropolitan Atlanta at some time during the year of interest
• Who have one or more of the developmental disabilities being tracked

Developmental Disabilities Tracked by MADDSP

Autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) is a developmental disability that can cause significant social, communication and behavioral challenges. There is often nothing about how people with ASD look that sets them apart from other people, but people with ASD may communicate, interact, behave, and learn in ways that are different from most other people. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged. Some people with ASD need a lot of help in their daily lives; others need less.

A diagnosis of ASD now includes several conditions that used to be diagnosed separately: autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome. These conditions are now all called autism spectrum disorder.

Cerebral palsy (CP)

Cerebral palsy (CP) is a group of disorders that affect a person's ability to move and maintain balance and posture. CP is caused by abnormal development of the brain or damage to the developing brain that affects a child's ability to control their muscles. CP does not get worse over time, though the exact symptoms can change over a person's lifetime. All people with CP have difficulty with movement and posture. Many also have related conditions such as intellectual disability, seizures, problems with vision or speech, changes in the spine (such as scoliosis), or joint problems (such as contractures).