Lifetime prevalence of learning disability among US children.

OBJECTIVE Our goal was to examine the lifetime prevalence of learning disability by sociodemographic and family-functioning characteristics in US children, with particular attention paid to the children with special health care needs. METHODS By using data from the National Survey of Children's Health, we calculated lifetime prevalence of learning disability using a question that asked whether a doctor or other health care or school professional ever told the survey respondent that the child had a learning disability. Children with and those without special health care needs were classified on the basis of how many of 5 definitional criteria for children with special health care needs they met (0-5). Bivariate and multivariate statistical methods were used to assess independent associations of selected sociodemographic and family variables with learning disability. RESULTS The lifetime prevalence of learning disability in US children is 9.7%. Although prevalence of learning disability is lower among average developing children (5.4%), it still affected 2.7 million children compared with 3.3 million (27.8%) children with special health care needs. As the number of definitional criteria children with special health care needs met increased from 1 to 5, so did the prevalence of learning disability (15.0%, 27.1%, 41.6%, 69.3%, and 87.8%, respectively). In the adjusted logistic regression model, in addition to the number of definitional criteria the children met, variables associated with the increased odd ratios of learning disability were lower education, all categories of poverty <300% of the federal poverty level, being male, increasing age, having a 2-parent stepfamily or other family structure, being adopted, presence of a smoker, respondent's higher responses on aggravation in parenting scale, sharing ideas with the child less than very well, and never, rarely, or sometimes discussing serious disagreements calmly. CONCLUSIONS Although more than half of lifetime prevalence of learning disability occurred in children with special health care needs, it is a significant morbidity in average-developing children as well. Learning disabilities represent important comorbidities among children with special health care needs.