Official MADDSP and MADDS Surveillance Case Definitions

Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) Case Definitions

Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is defined as a group of behaviors indicating social, communicative, and behavioral impairment or abnormalities. The essential features of ASD are (a) impaired reciprocal social interactions, (b) delayed or unusual communication styles, and (c) restricted or repetitive behavior patterns.

A child is included in MADDSP as a confirmed case of ASD if he or she displays behaviors (as described on a comprehensive evaluation by a qualified professional) that are consistent with the diagnostic criteria listed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) for any of the following conditions: Autistic Disorder, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS, including Atypical Autism), or Asperger's Disorder.

To determine MADDSP case status, information is abstracted from health and education records and then reviewed by an ASD clinician reviewer using a coding scheme based on DSM-IV-TR criteria for Autistic Disorder, PDD-NOS, and Asperger’s Disorder.

A qualified professional is defined as a medical, clinical, or educational professional in a position to observe children with developmental disabilities (including, but not limited to, psychologist, physician, teacher, learning specialist, speech/language pathologist, occupational therapist, physical therapist, nurse, social worker).

An ASD clinician reviewer is defined as a qualified diagnostician with specialized training and experience in autism assessment and diagnosis.

Cerebral Palsy

Cerebral palsy (CP) is defined as a group of permanent disorders of the development of movement and posture that are attributed to non-progressive disturbances that occurred in the developing brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, mental ability, communication, and behavior; CP is also often accompanied by co-occurring epilepsy; and by secondary musculoskeletal problems.* The impairment of motor function may result in paresis, involuntary movement, or incoordination. CP does not include motor disorders that are transient, that result from progressive disease of the brain, or that are due to spinal cord abnormalities/injuries. CP acquired after birth (post-neonatal CP) are included as cases in MADDSP.

A child is included in MADDSP as a confirmed CP case if he or she was diagnosed with CP or has a description of physical findings consistent with CP noted in clinical evaluation(s) at age 2 or older by a qualified professional. To determine MADDSP case status, information is abstracted from health and education records and then reviewed by a CP clinician reviewer to determine if the diagnostic information and/or physical findings are consistent with CP.

A qualified professional is defined as a physician (doctor of medicine/MD or doctor of osteopathy/DO), physical therapist (PT), occupational therapist (OT), nurse practitioner (NP), physician assistant (PA), or clinical nurse specialist (CNS).

A CP clinician reviewer is defined as a clinician with an advanced degree, direct clinical experience, and specialized training and/or certification in the assessment and/or diagnosis of children with CP (e.g., developmental pediatrician, OT, PT).

*Modification of the definition by Rosenbaum L, Paneth N, Leviton A, Goldstein M, Bax, M. The definition and classification of cerebral palsy. Dev Med Child Neurol. 2007;49(Suppl 109):8-14.

Hearing Loss

Hearing loss is defined as an unaided, measured, bilateral, pure-tone hearing loss at frequencies of 500, 1000, and 2000 hertz averaging 40 decibels (dB) or more in the better ear on the most recent audiological evaluation conducted by a qualified professional. In the absence of a measured, bilateral hearing loss, children meet the case definition if their health or education records include a description of a hearing loss of 40 dB or more in the better ear (e.g., profound sensorineural hearing loss) by a qualified professional. Severity is defined on the basis of the following Hearing loss levels (measured in the better ear): moderate (a hearing loss of 40-69 dB), severe (a hearing loss of 70-89 dB), and profound (a hearing loss of 90 dB).

Trained abstractors review audiological evaluations by a qualified professional in health and education records. If the above case definition is met, then hearing test results are abstracted and case status is assigned.

A qualified professional is defined as a licensed or certified audiologist or qualified physician (otolaryngologist / ENT, otologist, neurotologist).

Intellectual Disability

Intellectual disability is defined as a condition marked by an intelligence quotient (IQ) of ≤70 on the most recently administered psychometric test. In the absence of an IQ score, a written statement by a psychometrist that, in the context of testing, a child’s intellectual functioning falls within the intellectual disability range is acceptable. The severity of intellectual disability is defined according to the following International Classification of Disease, Ninth Edition, Clinical Modification (ICD-9-CM) categories: mild (an IQ of 50-70), moderate (an IQ of 35-49), severe (an IQ of 20-34), and profound (an IQ of <20).

Trained abstractors review intelligence and developmental test results by qualified professionals in health and education records. If the above case definition is met, then intelligence and developmental test results are abstracted and case status is assigned.

A psychometrist is defined as a medical, clinical or educational professional who administers and scores psychological and neuropsychological measures.

It is currently preferable to use the term "intellectual disability" instead of "mental retardation."

Vision Impairment

Vision impairment is defined as a measured visual acuity of 20/70 or worse in the better eye, even after vision is corrected to the extent possible, such as with glasses. The vision results must come from the most recent eye exam or vision evaluation by a qualified professional. In the absence of a measured visual acuity, a child is considered a case if an education or school record includes (a) a functional description, by a qualified professional, of visual acuity of 20/70 or worse (e.g., light perception only) or (b) a statement by a qualified professional that the child has low vision or blindness. Severity of visual impairment is defined using the WHO categories low vision (20/70 – 20/400) and blindness (worse than 20/400) orthe U.S.A. categories of low vision (20/70 to better than 20/200) and legal blindness (20/200 or worse).

Trained abstractors review the eye exam or vision evaluation results by qualified professionals in health and education records. If the above case definition is met, then eye exam and vision evaluation results are abstracted and case status is assigned.
A qualified professional is defined as an ophthalmologist or neuro-ophthalmologist, optometrist, orthoptist, ophthalmic registered nurse, or vision specialist in a special education or early intervention program.

Metropolitan Atlanta Developmental Disabilities Study (MADDS) Case Definitions

Cerebral Palsy

Cerebral palsy was defined as an inclusive term that describes a group of nonprogressive disorders occurring in young children in which abnormalities of the brain cause impairment of motor function. The impairment of motor function may result in paresis, involuntary movement, or incoordination.

Children with postneonatally acquired cerebral palsy are included. Motor disorders that are transient, disorders that result from progressive disease of the brain, and motor disorders due to spinal cord abnormalities were not included. Records were examined for any mention of CP as well as any indication of CP from physical findings (e.g., spasticity, athetoid movements). Abstracted information was reviewed by a clinician with an advanced degree, direct clinical experience, and specialized training and/or certification in the assessment and/or diagnosis of children with CP (e.g., developmental pediatrician).

Hearing Loss

Hearing loss is defined as an unaided, measured, bilateral, pure-tone hearing loss at frequencies of 500, 1000, and 2000 hertz averaging 40 decibels (dB) or more in the better ear on an audiological evaluation by a qualified professional. In the absence of a measured, bilateral hearing loss, children meet the case definition if their source records include a description of a hearing loss of 40 dB or more in the better ear (e.g., profound sensorineural hearing loss) by a qualified professional. Severity is defined on the basis of the following hearing loss levels (measured in the better ear): moderate (a hearing loss of 40-69 dB), severe (a hearing loss of 70-89 dB), and profound (a hearing loss of ≥90 dB).

Mental Retardation/Intellectual Disability

Mental retardation/Intellectual disability was defined as an IQ of 70 or less on the most recent psychometric test performed by a psychometrist. Children with Down syndrome were considered to have MR/ID in the absence of an IQ score. In some instances, a psychometrist was unable to complete an intelligence test because of a child's extremely low level of functioning. When this occurred, a judgment by the professional of profound MR (IQ <20) was accepted. The severity of intellectual disability is defined according to the following International Classification of Disease, Ninth Edition, Clinical Modification (ICD-9-CM) categories: mild (an IQ of 50-70), moderate (an IQ of 35-49), severe (an IQ of 20-34), and profound (an IQ of <20).

It is currently preferable to use the term "intellectual disability" instead of "mental retardation", yet at the time that MADDS was conducted and the prevalence results were published “mental retardation” was the commonly acceptable term.

Vision Impairment

Vision impairment is defined as a measured visual acuity of 20/200 or worse in the better eye with correction on an eye exam or vision evaluation by a qualified physician or vision professional. In the absence of a measured visual acuity, a child is considered a case if a source record includes (a) a functional description, by a qualified physician or vision professional, of visual acuity of 20/200 or worse (e.g., light perception only) or (b) a statement by a qualified physician or vision professional that the child has low vision or blindness. Severity of visual impairment is defined using the WHO categories low vision (20/70 – 20/400) and blindness (worse than 20/400) orthe U.S.A. categories of low vision (20/70 to better than 20/200) and legal blindness (20/200 or worse).

Epilepsy

Epilepsy was defined as a history of two or more epileptic seizures diagnosed by a physician. Clusters of seizures (two or more) that occurred within a 24 hour period were considered as a single seizure. Children who only had simple febrile seizures were not included as having epilepsy. Children with febrile status epilepticus were included as having epilepsy only if they otherwise qualified on the basis of afebrile seizures.