title: Sampling design for the Study of Cardiovascular Risks in Adolescents (ERICA).
abstract: The Study of Cardiovascular Risk in Adolescents (ERICA) aims to estimate the prevalence of cardiovascular risk factors and metabolic syndrome in adolescents (12-17 years) enrolled in public and private schools of the 273 municipalities with over 100,000 inhabitants in Brazil. The study population was stratified into 32 geographical strata (27 capitals and five sets with other municipalities in each macro-region of the country) and a sample of 1,251 schools was selected with probability proportional to size. In each school three combinations of shift (morning and afternoon) and grade were selected, and within each of these combinations, one class was selected. All eligible students in the selected classes were included in the study. The design sampling weights were calculated by the product of the reciprocals of the inclusion probabilities in each sampling stage, and were later calibrated considering the projections of the numbers of adolescents enrolled in schools located in the geographical strata by sex and age.
authors.affiliation: Escola Nacional de Ciências Estatísticas, Fundação Instituto Brasileiro de Geografia e Estatística, Rio de Janeiro, Brasil.
authors.forename: Mauricio Teixeira Leite de
authors.initials: MT
authors.lastname: Vasconcellos
authors.affiliation: Escola Nacional de Ciências Estatísticas, Fundação Instituto Brasileiro de Geografia e Estatística, Rio de Janeiro, Brasil.
authors.forename: Pedro Luis do Nascimento
authors.initials: PL
authors.lastname: Silva
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Moyses
authors.initials: M
authors.lastname: Szklo
authors.affiliation: Núcleo de Estudos da Saúde do Adolescente, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Maria Cristina Caetano
authors.initials: MC
authors.lastname: Kuschnir
authors.affiliation: Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil.
authors.forename: Carlos Henrique
authors.initials: CH
authors.lastname: Klein
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Gabriela de Azevedo
authors.initials: Gde A
authors.lastname: Abreu
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Laura Augusta
authors.initials: LA
authors.lastname: Barufaldi
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Katia Vergetti
authors.initials: KV
authors.lastname: Bloch
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D015995:Prevalence; D012107:Research Design; D012111:Residence Characteristics; D012307:Risk Factors; D018401:Sample Size; D013334:Students / Q000706:statistics & numerical data