Nancy S. Doernberg

Prevalence of cerebral palsy in 8-year-old children in three areas of the United States in 2002: a multisite collaboration.

OBJECTIVE. The goal was to estimate the prevalence of cerebral palsy and cerebral palsy subtypes among children in 3 areas of the United States by using a population-based surveillance system. METHODS. Using methods developed by the Centers for Disease Control and Prevention Metropolitan Atlanta Developmental Disabilities Surveillance Program, investigators from the Autism and Developmental Disabilities Monitoring Network conducted surveillance of cerebral palsy among 8-year-old children living in northern Alabama, metropolitan Atlanta, and southeastern Wisconsin in 2002 (N = 114897). Cross-sectional data were collected through retrospective record review from multiple sources. Cases were linked to birth certificate and census files to obtain additional information. Period prevalence estimates were calculated per 1000 children 8 years of age. RESULTS. The average prevalence of cerebral palsy across the 3 sites was 3.6 cases per 1000, with notably similar site-specific prevalence estimates (3.3 cases per 1000 in Wisconsin, 3.7 cases per 1000 in Alabama, and 3.8 cases per 1000 in Georgia). At all sites, prevalence was higher in boys than girls (overall boy/girl ratio: 1.4:1). Also, at all sites, the prevalence of cerebral palsy was highest in black non-Hispanic children and lowest in Hispanic children. At all sites, the prevalence among children living in low- and middle-income neighborhoods was higher than that among children living in high-income neighborhoods. Spastic cerebral palsy was the most common subtype (77% of all cases), with bilateral spastic cerebral palsy dominating the spastic group (70%). CONCLUSION. These findings contribute new knowledge to the epidemiology of cerebral palsy in the United States. The similarities in prevalence rates and patterns of cerebral palsy reported for 8-year-old children at 3 geographically distinct sites provide evidence of the reliability of the surveillance methods used by the Autism and Developmental Disabilities Monitoring Network.

Prevalence and functioning of children with cerebral palsy in four areas of the United States in 2006: a report from the Autism and Developmental Disabilities Monitoring Network.

AIM To estimate the prevalence of cerebral palsy (CP) and the frequency of co-occurring developmental disabilities (DDs), gross motor function (GMF), and walking ability using the largest surveillance DD database in the US. METHODS We conducted population-based surveillance of 8-year-old children in 2006 (N=142,338), in areas of Alabama, Georgia, Wisconsin, and Missouri. This multi-site collaboration involved retrospective record review at multiple sources. We reported CP subtype, co-occurring DDs, Gross Motor Function Classification System (GMFCS) level, and walking ability as well as CP period prevalence by race/ethnicity and sex. RESULTS CP prevalence was 3.3 (95% confidence interval [CI]: 3.1-3.7) per 1000 and varied by site, ranging from 2.9 (Wisconsin) to 3.8 (Georgia) per 1000, 8-year olds (p<0.02). Approximately 81% had spastic CP. Among children with CP, 8% had an autism spectrum disorder and 35% had epilepsy. Using the GMFCS, 38.1% functioned at the highest level (I), with 17.1% at the lowest level (V). Fifty-six percent were able to walk independently and 33% had limited or no walking ability. INTERPRETATION Surveillance data are enhanced when factors such as functioning and co-occurring conditions known to affect clinical service needs, quality of life, and health care are also considered.

Prevalence of cerebral palsy, co‐occurring autism spectrum disorders, and motor functioning – Autism and Developmental Disabilities Monitoring Network, USA, 2008

The aim of this study was to report the prevalence and characteristics of children with cerebral palsy (CP).

Trends in the Prevalence of Autism Spectrum Disorder, Cerebral Palsy, Hearing Loss, Intellectual Disability, and Vision Impairment, Metropolitan Atlanta, 1991–2010

This study examined the prevalence and characteristics of autism spectrum disorder (ASD), cerebral palsy (CP), hearing loss (HL), intellectual disability (ID), and vision impairment (VI) over a 15–20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991–2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993–2010. The average annual increase in ASD prevalence was 9.3% per year from 1996–2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000–2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991–2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000), CP, (3.5 per 1,000), HL (1.4 per 1,000) and VI (1.3 in 1,000), with a growing urgency for children with ASD.

Prevalence of cerebral palsy: Autism and Developmental Disabilities Monitoring Network, three sites, United States, 2004†

BACKGROUND Cerebral palsy (CP) is the most common cause of motor disability in children and an important public health issue in the United States. The Autism and Developmental Disabilities Monitoring (ADDM) Network is a multisite program funded by the Centers for Disease Control and Prevention to determine trends in the prevalence of children with developmental disabilities, including CP, in the United States. This report describes population-based estimates of CP prevalence among 8-year-old children in three sites in the United States. METHODS The ADDM Network conducted surveillance of CP among 8-year-old children living in north central Alabama, metropolitan Atlanta, and south central Wisconsin in 2004 (N = 68,272). This multisite collaboration involved the retrospective collection, linking, and analysis of data from multiple service providers and the population census estimates. RESULTS The average prevalence of CP in 2004 across the three sites was 3.3 per 1,000 (95% confidence interval, 2.9-3.8). The prevalence was significantly higher in boys than in girls overall (male/female ratio, 1.4:1). The most common subtype across all three sites was spastic CP, ranging from 85% in Georgia to 89% in Alabama and Wisconsin. CONCLUSIONS Ongoing, systematic, population-based surveillance in different areas of the United States is needed to describe and monitor CP prevalence. In addition, enhancing the surveillance system to include information about functional abilities is needed to better understand the public health impact of CP and strategies for improving quality of life and participation in activities at home and in the community.

Changes in autism spectrum disorder prevalence in 4 areas of the United States

BACKGROUND We sought to describe autism spectrum disorder (ASD) population characteristics and changes in identified prevalence across 3 time periods. METHODS Children with a potential ASD were identified through records abstraction at multiple sources with clinician review based on Diagnostic and Statistical Manual (DSM-IV-TR) criteria. Multisite, population-based data from the Autism and Developmental Disabilities Monitoring (ADDM) Network were analyzed from areas of Arizona (AZ), Georgia (GA), Maryland (MD), and South Carolina (SC). Participants were 8-year-old children (born in 1992, 1994, or 1996) in 2000, 2002, or 2004 (and children born in 1988 residing in metropolitan Atlanta in 1996) who had been evaluated for a variety of developmental concerns at education and/or health sources. RESULTS From 2000 to 2004, the identified prevalence of the ASDs per 1,000 8-year-old children showed significant increases of 38% in GA and 72% in MD and a nonsignificant increase of 26% in AZ. ASD prevalence was relatively stable in SC with a nonsignificant decrease of 17%. Males had a higher identified prevalence of ASD in all years. Increases among racial, ethnic, and cognitive functioning subgroups varied by site and surveillance year. More children were classified with an ASD by community professionals over time, except in AZ. CONCLUSIONS There was a trend toward increase in identified ASD prevalence among 8-year-old children who met the surveillance case definition in 3 of the 4 study sites from 2000 to 2004. Some of the observed increases are due to improved ascertainment; however, a true increase in ASD symptoms cannot be ruled out. These data confirm that the prevalence of ASDs is undergoing significant change in some areas of the United States and that ASDs continue to be of urgent public health concern.

Birth Prevalence of Cerebral Palsy: A Population-Based Study

OBJECTIVE: Population-based data in the United States on trends in cerebral palsy (CP) birth prevalence are limited. The objective of this study was to examine trends in the birth prevalence of congenital spastic CP by birth weight, gestational age, and race/ethnicity in a heterogeneous US metropolitan area. METHODS: Children with CP were identified by a population-based surveillance system for developmental disabilities (DDs). Children with CP were included if they were born in metropolitan Atlanta, Georgia, from 1985 to 2002, resided there at age 8 years, and did not have a postneonatal etiology (n = 766). Birth weight, gestational age, and race/ethnicity subanalyses were restricted to children with spastic CP (n = 640). Trends were examined by CP subtype, gender, race/ethnicity, co-occurring DDs, birth weight, and gestational age. RESULTS: Birth prevalence of spastic CP per 1000 1-year survivors was stable from 1985 to 2002 (1.9 in 1985 to 1.8 in 2002; 0.3% annual average prevalence; 95% confidence interval [CI] −1.1 to 1.8). Whereas no significant trends were observed by gender, subtype, birth weight, or gestational age overall, CP prevalence with co-occurring moderate to severe intellectual disability significantly decreased (−2.6% [95% CI −4.3 to −0.8]). Racial disparities persisted over time between non-Hispanic black and non-Hispanic white children (prevalence ratio 1.8 [95% CI 1.5 to 2.1]). Different patterns emerged for non-Hispanic white and non-Hispanic black children by birth weight and gestational age. CONCLUSIONS: Given improvements in neonatal survival, evidence of stability of CP prevalence is encouraging. Yet lack of overall decreases supports continued monitoring of trends and increased research and prevention efforts. Racial/ethnic disparities, in particular, warrant further study.

Public health monitoring of developmental disabilities with a focus on the autism spectrum disorders

Developmental disabilities (DDs) are conditions characterized by physical, cognitive, psychological, sensory, adaptive, and/or communication impairments manifested during development. Approximately 17% of individuals in the United States 18 years and younger have a DD, and for most children the cause of their condition is unknown. Of particular interest are the autism spectrum disorders (ASDs), characterized by unusual social, communication, and behavioral development. Previously autism was thought to be a rare condition, but the number of children receiving services for an ASD has increased dramatically in the last decade. Concerns about increases in DDs, particularly ASDs, their causes, and the high costs of intervention have highlighted the need for systematic public health monitoring. Service provider data, such as annual reporting of special education services or of state DD programs, do not provide a complete estimate of the rates for DDs, including ASDs. Unlike genetic metabolic disorders or congenital hearing loss (HL) for which newborn screening programs can provide accurate prevalence rates, there are currently no genetic or biologic markers for the ASDs to enable consistent and early identification of affected children. Centers for Disease Control and Preventions (CDC) Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) is a model for population monitoring of ASDs/DDs that has been implemented in other states. This article discusses the role of ASD/DD tracking in public health, as well as the challenges of ASD/DD tracking, including case definition and identification, associated conditions, linkages, and data access.

Feasibility and reliability of classifying gross motor function among children with cerebral palsy using population-based record surveillance

For conditions with wide-ranging consequences, such as cerebral palsy (CP), population-based surveillance provides an estimate of the prevalence of case status but only the broadest understanding of the impact of the condition on children, families or society. Beyond case status, information regarding health, functional skills and participation is necessary to fully appreciate the consequences of the condition. The purpose of this study was to assess the feasibility and reliability of enhancing population-based surveillance by classifying gross motor function (GMF) from information available in medical records of children with CP. We assessed inter-rater reliability of two GMF classification methods, one the Gross Motor Function Classification System (GMFCS) and the other a 3-category classification of walking ability: (1) independently, (2) with handheld mobility device, or (3) limited or none. Two qualified clinicians independently reviewed abstracted evaluations from medical records of 8-year-old children residing in southeast Wisconsin, USA who were identified as having CP (n = 154) through the Centers for Disease Control and Preventions Autism and Developmental Disabilities Monitoring Network. Ninety per cent (n = 138) of the children with CP had information in the record after age 4 years and 108 (70%) had adequate descriptions of gross motor skills to classify using the GMFCS. Agreement was achieved on 75.0% of the GMFCS ratings (simple kappa = 0.67, 95% confidence interval [95% CI 0.57, 0.78], weighted kappa = 0.83, [95% CI 0.77, 0.89]). Among case children for whom walking ability could be classified (n = 117), approximately half walked independently without devices and one-third had limited or no walking ability. Across walking ability categories, agreement was reached for 94% (simple kappa = 0.90, [95% CI 0.82, 0.96], weighted kappa = 0.94, [95% CI 0.89, 0.98]). Classifying GMF in the context of active records-based surveillance is feasible and reliable. Future surveillance efforts that include functional level among children with cerebral palsy may provide important information for monitoring the impact of the condition for programmatic and policy purposes.

The role of migration and choice of denominator on the prevalence of cerebral palsy

Differential migration and choice of denominator have been hypothesized to contribute to differences between period prevalence and birth prevalence of cerebral palsy (CP). The purpose of this study was to evaluate the effects of migration and choice of denominator on the prevalence of CP.