Supplementary Material for: Intellectual Disability in a Birth Cohort: Prevalence, Etiology, and Determinants at the Age of 4 Years Karam S.M. Barros A.J.D. Matijasevich A. dos Santos I.S. Anselmi L. Barros F. Leistner-Segal S. Félix T.M. Riegel M. Maluf S.W. Giugliani R. Black M.M. 10.6084/m9.figshare.3808140.v1 https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Intellectual_Disability_in_a_Birth_Cohort_Prevalence_Etiology_and_Determinants_at_the_Age_of_4_Years/3808140 <i>Background:</i> Intellectual disability (ID), characterized by impairments in intellectual function and adaptive behavior, affects 1-3% of the population. Many studies investigated its etiology, but few are cohort studies in middle-income countries.<i>Aims:</i> To estimate prevalence, etiology, and factors related to ID among children prospectively followed since birth in a Southern Brazilian city (Pelotas). <i>Methods:</i> In 2004, maternity hospitals were visited daily and births were identified. Live-born infants (n = 4,231) whose family lived in the urban area have been followed for several years. At the age of 2 and 4 years, performances in development and intelligence tests were evaluated using the Battelle Developmental Inventory and Wechsler Intelligence Scale, respectively. Children considered as having developmental delay were invited to attend a genetic evaluation. <i>Results:</i> At 4 years of age, the prevalence of ID was 4.5%, and the etiology was classified into 5 groups: environmental (44.4%), genetic (20.5%), idiopathic (12.6%), neonatal sequelae (13.2%), other diseases (9.3%). Most children presented impairment in two or more areas of adaptive behavior. There was no difference in prenatal care attendance or maternal schooling among the groups. <i>Conclusion:</i> For about 40% of children, ID was attributed to nonbiological factors, suggesting that the rate may be reduced with appropriate interventions early in life. 2016-09-07 10:36:15 Cohort studies Developmental delay Intellectual disability Mental retardation Prevalence