Studies - 1982 Cohort

Scientific Community

The 1982 Birth Cohort of Pelotas is the largest epidemiological longitudinal study realized in Latin American countries. The research was conducted in stages, and the first one was called Perinatal Study. At this stage, all the births, during the period of January and December of Pelotas’ hospitals were identified. There were 7.392 births, but, since the research should focus only on babies who were born alive and whose mothers lived in the urban area of Pelotas, there were 5.914 able babies to participate in the study.

Follow-up studies:
In 1982, doctors of the Center of Epidemiological Research (CPE) team visited daily the three maternity hospitals of the city in order to interview the mothers that had given birth and looked at the newborns. The mothers were interviewed about a series of biological, demographic, socioeconomic and assistance factors. The neonates’ data included sex, singleton or twin pregnancy, gestational age, perinatal morbidity and mortality and type of parturition. The mothers were weighted and measured before parturition, and the babies were weighted just after their births. The team who did this job was previously trained in a pilot study.

After this identification stage, many follow-up visits to the babies and their mothers happened.

1983 - It was realized a follow-up analysis of all about-12-month babies who were born between January and April of 1982. At this moment, it was used the data informed by the mothers at the hospital. Of the 1.916 searched participants, 1.457 children were found, and this fact represented a loss of 20%. In this follow-up study, the children were weighted and measured, and their mothers or sponsors were interviewed about their socioeconomic, environmental, and demographic features, as well as about features related to their diet, hospital morbidity, and health services use.

1984 - It was realized a census of all the 68.590 houses of Pelotas in order to find all 1982 born children. The initiative aimed to reduce the loss of 20% that happened in 1983. This follow-up analysis found 4.933 children, which meant a loss of 12,8% instead. Through the census, it was possible to know that 45% of the families had changed their addresses inside the city, since the first contact two years before. In this second follow-up, children were weighted and measured and their mothers were also interviewed again. Besides the questions asked on the previous follow-up, the researchers collected information about some common diseases and the children’s psychomotor development. They also collected data about the mothers’ health, and all those data were connected to the information already gathered in the perinatal study and in the first follow-up analysis.

1986 - It was realized a new census of all houses of Pelotas. The fieldwork lasted from December 1985 to April 1986 and the children were, in average, 43 months old. 4.742 children were found, which represented 84,1% of all participants. Again, socioeconomic, demographic, environmental and food factors were investigated. Among the new elements of this follow-up analysis was a brief interview with the children.

1995 - It was realized a follow-up with 20% of the 1982 Birth Cohort. The location method used was the same as the previous follow-up data. 715 participants were found, and they were, in average, at the age of 13.

1996 - It was realized a follow-up with 27% of the 1982 Birth Cohort. 1.597 adolescents were searched, but only 1.076 of them were found. Their average age was of 14,7 years.

1997 a 2001 - It was realized an ethnographic study with 96 participants of the 1982 Birth Cohort, who were between 15 and 19 years old.

2000 - It was realized a follow-up with all the young-man participants. Their identification was made through the Brazilian conscription. 3.037 participants were waited, but only 2.250 of them were found, which is believed to be the total number of male participants who lived in Pelotas at that time. In this follow-up, all questionnaires made about the current socioeconomic conditions, life habits (smoking, drugs, and physical activity), diet, work, morbidity, education, medication use, sexuality, mental health, and health services use. Through these data, it was possible to evaluate the relationship between respiratory diseases and low birth weight and intrauterine growth retardation.

2001 - It was realized a research with 27% of the 1982 Birth Cohort participants, when 1.031 participants at the average age of 18,9 years were interviewed.

2004-05 - It was realized a census of 98 thousand houses from Pelotas to find all 1982 Birth Cohort participants. 4.297 participants were found, at the average age of 22,8 years. In this follow-up, 282 deaths were detected since their births. Besides the standard questionnaire, there was a blood-sample collection of 3.914 people (91,1% of all participants). Through this initiative, it was created the 1982 Birth Cohort DNA Database.

The details about the 1982 Birth Cohort studies are presented in innumerous scientific articles, which have been written by the CPE researchers, and by the students of the Postgraduate Program in Epidemiology at UFPel.
You can read some of those papers that are available at open access journals.
The instruments and the questionnaire used in the main follow-up studies and analyses are available for the scientific community.

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Epidemiology Postgraduate Program- Centre of Epidemiological Research