[Methodology of the Pelotas birth cohort study from 1982 to 2004-5, Southern Brazil].
OBJECTIVE
To describe the methods employed in the longitudinal and follow-up studies of children born in Pelotas (Southern Brazil) in 1982.


METHODS
The cohort began with a perinatal health survey that included all 6,011 children born in maternity wards in Pelotas in 1982. The 5,914 children born alive in the city were included in the follow-up studies. By 2004-5, we had conducted eight follow-ups, which consisted of the administration of questionnaires to mothers and/or cohort members, depending on age, in addition to anthropometric and clinical examination. Cohort subjects are described in terms of demographic, socioeconomic, and health-related variables collected during early follow-up studies, which are used as exposure variables.


RESULTS
The majority of subjects in the cohort were followed for 23 years and on multiple occasions. The most successful follow-ups were those preceded by a city census. Using this method, we were able to locate 87.2% of subjects in 1984 (mean age 19 months), 84.1% in 1986 (mean age 43 months), and 77.4% in 2004-5, and 77.4% in 2004-5 (mean age 23 years).


CONCLUSIONS
Birth cohort studies can be carried out successfully in developing countries, and the methods employed in this life-cycle study have allowed us to investigate the influence of early exposures in determining disease outcomes in adult life.
Barros
Fernando C
FC
Programa de Pós-Graduação em Saúde e Comportamento, Universidade Católica de Pelotas, Pelotas, RS, Brasil.
Victora
Cesar G
CG
Horta
Bernardo L
BL
Gigante
Denise P
DP
D000293:Adolescent; D000328:Adult; D001723:Birth Rate; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D015331:Cohort Studies; D003906:Developing Countries; D015340:Epidemiologic Research Design; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D008297:Male; D008403:Mass Screening; D012959:Socioeconomic Factors; D055815:Young Adult