Search

Background: Previous studies of the frequency of cerebral palsy in the United States have found excess prevalence in black children relative to other groups. Whether the severity of cerebral palsy differs between black and white children has not previously been investigated.Methods: A population-based surveillance system in 4 regions of the United States identified 476 children with cerebral palsy among 142,338 8-year-old children in 2006. Motor function was rated by the Gross Motor Function Classification System and grouped into 3 categories of severity. We used multiple imputation to account for missing information on motor function and calculated the race-specific prevalence of each cerebral palsy severity level.Results: The prevalence of cerebral palsy was 3.7 per 1000 black children and 3.2 per 1000 white children (prevalence odds ratio [OR] = 1.2 [95% confidence interval = 1.0-1.4]). When stratified by severity of functional limitation, the racial disparity was present only for severe cerebral palsy (black vs. white prevalence OR=1.7 [1.1-2.4]). The excess prevalence of severe cerebral palsy in black children was evident in term and very preterm birth strata.Conclusion: Black children in the United States appear to have a higher prevalence of cerebral palsy overall than white children, although the excess prevalence of cerebral palsy in black children is seen only among those with the most severe limitations. Further research is needed to explore reasons for this disparity in functional limitations; potential mechanisms include racial differences in risk factors, access to interventions, and under-identification of mild cerebral palsy in black children. [ABSTRACT FROM AUTHOR]

Background: A 57% increase in the U.S. prevalence of autism spectrum disorders (ASD) for 8-year-old children born in 1994 versus 1998 was recently reported.Methods: To quantify the possible contributions of given risk/predictive factors on the recent ASD prevalence increase, we formulated a mathematical model based on the baseline risk factor prevalence (RFP), the proportionate change in RFP (cRFP), and the magnitude of the association between the risk factor and ASD [estimated relative risk (RR)]. We applied this model to several pregnancy-related factors (preterm, very preterm, low and very low birth weight, multiple birth, cesarean delivery, breech presentation, and assisted reproductive technology use). RFP and cRFP estimates for each factor were obtained from U.S. population-based surveillance datasets. Estimated RRs were obtained from a series of systematic literature reviews.Results: We estimate that each risk factor examined, alone or in various combinations, accounted for a very small proportion (<1%) of the ASD increase. Additionally, hypothetical scenarios indicate RFP, cRFP, and RR all need to be sizable for a risk factor to appreciably influence ASD prevalence.Conclusions: Thus, although various pregnancy factors have been found to be associated with ASDs, the contribution of many of these factors to the recently observed ASD increase is likely minimal. [ABSTRACT FROM AUTHOR]