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.

Health promotion initiatives at school related to overweight, insulin resistance, hypertension and dyslipidemia in adolescents: a cross-sectional study in Recife, Brazil

“…The sample is representative of the population of Recife, Brazil. A detailed description of the method can be found in Vasconcellos et al [16]. …”

“…Population estimates were obtained taking into account the complex sample design with weighting due to the different selection probabilities of the conglomerates (schools, grades/years and day-shift combinations, and classes) and later calibration by age and gender domains. The sample design can be found in Vasconcellos et al [16]. …”

Challenges for conducting blood collection and biochemical analysis in a large multicenter school-based study with adolescents: lessons from ERICA in Brazil

“…All students of randomly selected classes were invited to participate in ERICA, but only students of the morning classes participated in fasting blood collection and only adolescents aged between 12 and 17 years were eligible. Details of ERICA's study design and sampling are available in other studies 5,6 .…”

Non-communicable diseases in Brazil: a flood of data is coming!

“…Table 1 summarizes some observational studies addressing non-communicable diseases that were designed and funded in Brazil. [13][14][15][16][17][18][19][20] Indeed, these new studies with much more data will open up a new window with impacts on National Health System policies, professional activity, the industry and science on the bench.…”