The center that gathers data from 100 million Brazilians to demonstrate the impact of social conditions and programs on health

Maurício Lima Barreto

Researcher of Collective Health at the Federal University of Bahia (UFBA) and Ph.D. in Epidemiology from the University of London
Project: Assessing the impact of social factors and interventions on healthy growth and development: the cohort of 100 million Brazilians

One of the most important factors for drawing conclusions in scientific studies is the sample size. In general, the larger it is, the more accurate and universal the results derived from it will be. Imagine, now, a sample that covers half the Brazilian population or, more precisely, 114 million Brazilians.

This was exactly the size of a gigantic database developed in a project proposed by the epidemiologist Maurício Barreto, a researcher at the Oswaldo Cruz Foundation (Fiocruz) and Ph.D. in Epidemiology at the University of London. Funding allowed the researcher to create the first Health Data and Knowledge Integration Center, called Cidacs. Cidacs is comparable to similar international research data institutions in Canada and Europe.

Comprised of data from the Cadastro Único (CadÚnico) and Bolsa Família Program (2004 to 2015), Cidacs links this information to other databases, including the Mortality Information System (SIM, 2000 to 2015), Live Birth Information System (Sinasc de 2001 to 2015) and the Food and Nutrition Surveillance System (Sisvan), which is still under development. Together, they form the Cohort of 100 Million Brazilians, the largest in the country. In applied statistics, a cohort is a group of people who share a common event that occurred during the same period (e.g., the cohort of people who were born between 1960 and 1970; a cohort of married women between 1990 and 2000). This type of scientific study allows us to understand the impact of certain events on long-term development. For example: the effects of Bolsa Família on child mortality over the past ten years.

“Only developed countries like Canada, Switzerland and Scotland have cohorts the size of ours,” says Maurício. “Cidacs is innovative because it is the first of its kind in a developing, middle-income country.” The amount of information is so large that it was necessary to house part of the data on a supercomputer.

Having overcome the challenge of gathering and connecting (‘link’ or ‘linkage’, as they say in the jargon of data science) all these databases, the team is now incorporating Sinasc and CadÚnico to create the largest birth cohort in Brazil, with 24 million children. With this data set, it will be possible to study the effects of cesarean sections on infant mortality and the impacts of premature birth and diseases, such as zika, syphilis and others, on child development at a national scale.

Connecting official data on social and economic conditions of the population with clinical information on diseases and other conditions allows us to draw conclusions about how these factors, called social determinants, can be harmful to health. “It is also possible to assess whether social and income transfer programs can improve health indicators and how this is done in practice,” notes Maurício. “Demonstrating that this process of poverty reduction has important effects on health is on the agenda of organizations around the world.”

Since 2014, when it was set up, the center has served as a major generator of data and evidence related to the health impacts of social determinants and social programs. It has also guided the decision-making process, bridging the gap between science and policy and allowing for the generation of evidence-based public policies.

Currently, about 30 research projects use data from Cidacs, including studies on the effects of Bolsa Família among leprosy patients and the effect of social conditions on the onset of this disease. The data demonstrated that when a person with leprosy is a beneficiary of the Bolsa Família Program, adherence to treatment increases by about 22% and the cure rate increases by 26%. Studies show that the incidence of the disease can be up to 14% lower among families receiving government assistance.

The first surveys using the Cidacs database, which were part of the initial study funded by Grand Challenges Brazil, focused on the themes of maternal and child health detailed below and the impacts of the Bolsa Família Program (PBF) in this area. For example, after merging the CadÚnico data with Sinasc, the researchers observed that a major cause of death in children was infection, followed by congenital malformations and external causes, with two thirds of these deaths concentrated in the first year of life. The burden is greatest for those who live in rural areas, lack an adequate source of water supply, live in homes without running water, and whose mothers have limited schooling.

The center received additional funding from several organizations, including the Ministry of Health, Wellcome Trust, National Institute for Health Research (United Kingdom) and CNPq. And it has drawn the attention of organizations around the world, in addition to Brazilian and international public health professionals. “Our challenge now is to think of Cidacs as an autonomous and sustainable structure, capable of maintaining itself for many years,” says Maurício.