Cohorts are studies also known as longitudinal studies, which are based on the identification of a group of individuals and on their follow-up over a period of time. The term cohort was created for referring to groups of soldiers who marched together in Roman legions during the Roman Empire.
All children born between January the first and December the thirty-first of 1993, who lived in the urban area of Pelotas, participate in the epidemiological study known as 1993 Birth Cohort. This research was developed by researchers of the Center of Epidemiological Research (CPE) and by the Postgraduate Program in Epidemiology at the Federal University of Pelotas (UFPel).
The 1993 Birth Cohort started 11 years after the realization of the 1982 Birth Cohort. The first cohort was developed through the initiative of Professors Cesar Victora and Fernando Barros together with other researchers. The 1982 Birth Cohort included all 1982 births in Pelotas.
The aim of having two birth cohort studies with the same features, but a decade different, was to enable the comparison between the maternal-child populations’ features and the evolution of the main health indicators. Besides, with those studies, it is possible to evaluate the influence of premature factors that occur during childhood in health in the life cycle.
During the creation of the 1993 Pelotas Birth Cohort, the researchers had the funding of the European Economic Community. However, for the study development until now, a lot of institutions have been contributing, such as the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES), the National Program for Excellence Centers, the National Research Board, the Brazilian Ministry of Health, the National Board for Technological and Scientific Development (CNPq) and the Foundation of Support for Research of Rio Grande do Sul (FAPERGS).
The cohort studies are organized in stages that consist of the participants' development follow-up analyses. The 1993 Birth Cohort identified 5.249 births of alive babies and it has been following them until now. In all follow-up analyses, researchers collect a series of information that are afterwards analyzed and compared with many other available data of the same person and other participants from the same or other cohorts.
