Although low- and middle-income countries still bear the burden of major infectious diseases, chronic noncommunicable diseases are becoming increasingly common due to rapid demographic, epidemiologic, and nutritional transitions. However, information is generally scant in these countries regarding chronic disease incidence, social determinants, and risk factors. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) aims to contribute relevant information with respect to the development and progression of clinical and subclinical chronic diseases, particularly cardiovascular diseases and diabetes. In this report, the authors delineate the study's objectives, principal methodological features, and timeline. At baseline, ELSA-Brasil enrolled 15,105 civil servants from 5 universities and 1 research institute. The baseline examination (2008-2010) included detailed interviews, clinical and anthropometric examinations, an oral glucose tolerance test, overnight urine collection, a 12-lead resting electrocardiogram, measurement of carotid intima-media thickness, echocardiography, measurement of pulse wave velocity, hepatic ultrasonography, retinal fundus photography, and an analysis of heart rate variability. Long-term biologic sample storage will allow investigation of biomarkers that may predict cardiovascular diseases and diabetes. Annual telephone surveillance, initiated in 2009, will continue for the duration of the study. A follow-up examination is scheduled for 2012-2013.

Chronic diseases are a global problem, yet information on their determinants is generally scant in low- and middle-income countries. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) aims to contribute relevant information regarding the development and progression of clinical and subclinical chronic diseases, particularly cardiovascular diseases and diabetes, in one such setting. At Visit 1, we enrolled 15 105 civil servants from predefined universities or research institutes. Baseline assessment (2008–10) included detailed interviews and measurements to assess social and biological determinants of health, as well as various clinical and subclinical conditions related to diabetes, cardiovascular diseases and mental health. A second visit of interviews and examinations is under way (2012–14) to enrich the assessment of cohort exposures and to detect initial incident events. Annual surveillance has been conducted since 2009 for the ascertainment of incident events. Biological samples (sera, plasma, urine and DNA) obtained at both visits have been placed in long-term storage. Baseline data are available for analyses, and collaboration via specific research proposals directed to study investigators is welcome.

High blood pressure (HBP) is the leading risk factor for years of life lost in Brazil. Factors associated with HBP awareness, treatment and control need to be understood better. Our aim is to estimate prevalence, awareness, and types of anti-hypertensive treatment and to investigate the association of HBP control with social position. Data of 15,103 (54% female) civil servants in six Brazilian state capitals collected at the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline (2008-2010) were used to estimate prevalence and cross-sectional association of HBP control with education, per capita family income and self-reported race, using multiple logistic regression. Blood pressure was measured by the oscillometric method. 35.8% were classified as presenting HBP; 76.8% of these used anti-hypertensive medication. Women were more aware than men (84.8% v. 75.8%) and more often using medication (83.1% v. 70.7%). Adjusted HBP prevalence was, in ascending order, Whites (30.3%), Browns (38.2%) and Blacks (49.3%). The therapeutic schemes most used were angiotensin-converting enzyme inhibitors, in isolation (12.4%) or combined with diuretics (13.3%). Among those in drug treatment, controlled blood pressure was more likely in the (postgraduate) higher education group than among participants with less than secondary school education (PR = 1.21; 95% CI: 1.14–1.28), and among Asian (PR = 1.21; 95% CI: 1.12–1.32) and ‘Whites (PR = 1.19; 95% CI: 1.12–1.26) compared to Blacks. Socioeconomic and racial inequality—as measured by different indicators—are strongly associated with HBP control, beyond the expected influence of health services access.

ObjectiveTo evaluate the salt intake and urinary Na + /K + ratio in a randomized sample from an ethnically mixed urban population. MethodsA randomized residential sample of 2,268 individuals aged 25-64 in Vitória, ES, was selected, of whom 1,663 (73.3%) reported to the University Hospital for standardized tests. Salt, Na + and K + intake was estimated from 12-hour urine excretion (7 p.m. to 7 a.m.) and from the monthly salt consumption at home reported in the interview. Clinic arterial pressure was measured twice under standard conditions by two trained investigators, using mercury sphygmomanometry. The Student t and Tukey tests were utilized for statistical analysis. Saúde Pública 2003; 37(6) Hypertension and salt intake www.fsp.usp.br/rsp Molina MCB et al Urinary Na + excretion was higher in men and individuals of lower socioeconomic level (P<0.000). No difference between ethnic groups was observed. K + excretion was unrelated to socioeconomic level and ethnicity, but was significantly higher among men (25±18 vs. 22±18 mEq/12h; P=0.002). Positive linear correlation was observed between urinary Na + e xcretion and systolic (r=0.15) and diastolic (r=0.19) arterial pressure. Hypertensive individuals showed higher urinary Na + excretion and Na + /K + ratio than normotensive individuals. Reported salt intake was around 50% of the intake estimated from 12-hour urine collection (around 45% of 24-hour urinary excretion). Results Rev ConclusionsSalt intake is strongly influenced by socioeconomic level and may partially explain the higher prevalence of hypertension in lower socioeconomic classes.

This study evaluated the reproducibility and relative validity of the Food Frequency Questionnaire (FFQ) used in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Participants (n = 281) completed the FFQ and three food records on two occasions during a 12-month period. Energy and nutrient values from food records were disattenuated and log-transformed. Reproducibility and validity were assessed by the intra-class correlation coefficient (ICC). Agreement between the two methods was evaluated by classification in tertiles. In the evaluation of reproducibility, ICC estimated ranged from 0.55 to 0.83 for protein and vitamin E, respectively. On relative validity, ICC ranged from 0.20 to 0.72 for selenium and calcium, respectively. Exact and adjacent agreement between methods varied from 82.9% for vitamin E to 89% for lipids and calcium (mean 86%). Average disagreement was 13.6%. In conclusion, this FFQ showed satisfactory reliability for all nutrients and reasonable validity, especially for energy, macronutrients, calcium, potassium, and vitamins E and C.

OBJECTIVE:To develop a diet quality index and to analyze socioeconomic factors associated with low child diet quality. METHODS:A cross-sectional study was performed with a representative sample of 1,282 children aged between seven and ten years, living in the city of Vitória, Southeastern Brazil, in 2007. Children were randomly selected from 26 public schools and six private schools. Data on socioeconomic characteristics and life habits of children were obtained from a structured questionnaire, sent to homes and preferably completed by mothers. A food frequency questionnaire was created from studies performed with Brazilian children and tested in a public school. An index entitled Índice de Alimentação do Escolar (ALES -School Child Diet Index) was designed to assess diet quality, taking in consideration the nutritional recommendations for the Brazilian population and the habit of having breakfast. The association between diet quality and socioeconomic factors was analyzed using multinomial logistic regression. Adjusted odds ratios and 95% confi dence intervals were estimated for the variables that remained in the model. RESULTS:According to the ALES index, approximately 41% of the children studied had low diet quality (boys= 37.7%, girls= 42.7%, p= 0.179). There were no signifi cant differences between sex, age, maternal employment status and living with the mother and diet quality. The variables that remained associated with low diet quality were low maternal level of education (OR= 3.93; 95% CI: 2.58;5.99), father not present in the household (OR= 2.03; 95% CI: 1.68;2.99) and not having lunch at the table (OR= 1.47; 95% CI: 1.12;1.93). CONCLUSIONS:Low maternal level of education increased the probability of a child not consuming a good quality diet, whether due to lack of access to healthy foods and adequate information or poorer ability to discern what is healthy.

The objective of the study was to estimate the contribution of ultra-processed foods to total caloric intake and investigate whether it differs according to socioeconomic position. We analyzed baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil 2008-2010; N = 14.378) and data on dietary intake using a food frequency questionnaire, assigning it into three categories: unprocessed or minimally processed foods and processed culinary ingredients, processed foods, and ultra-processed foods. We measured the associations between socioeconomic position (education, per capita household income, and occupational social class) and the percentage of caloric contribution of ultra-processed foods, using generalized linear regression models adjusted for age and sex. Unprocessed or minimally processed foods and processed culinary ingredients contributed to 65.7% of the total caloric intake, followed by ultra-processed foods (22.7%). After adjustments, the percentage of caloric contribution of ultra-processed foods was 20% lower among participants with incomplete elementary school when compared to postgraduates. Compared to individuals from upper income classes, the caloric contribution of ultra-processed foods was 10%, 15% and 20% lower among the ones from the three lowest income, respectively. The caloric contribution of ultra-processed foods was also 7%, 12%, 12%, and 17% lower among participants in the lowest occupational social class compared to those from high social classes. Results suggest that the caloric contribution of ultra-processed foods is higher among individuals from high socioeconomic positions with a dose-response relationship for the associations.

The ELSA-Brasil (Estudo Longitudinal de Saúde do Adulto -Brazilian Longitudinal Study for Adult Health) is a cohort study composed of 15,105 adults followed up in order to assess the development of chronic diseases, especially diabetes and cardiovascular disease. Its size, multicenter nature and the diversity of measurements required effective and effi cient mechanisms of quality assurance and control. The main quality assurance activities (those developed before data collection) were: careful selection of research instruments, centralized training and certifi cation, pretesting and pilot studies, and preparation of operation manuals for the procedures. Quality control activities (developed during data collection and processing) were performed more intensively at the beginning, when routines had not been established yet. The main quality control activities were: periodic observation of technicians, test-retest studies, data monitoring, network of supervisors, and cross visits. Data that estimate the reliability of the obtained information attest that the quality goals have been achieved. 2Quality assurance and control in ELSA-Brasil Schmidt MI et al Health research aims primarily to fi nd answers to diverse health issues, and the integrity of results is strongly determined by the quality of the information produced. 1,5,6 To guarantee the quality of the data in the Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil -Brazilian Longitudinal Study for Adult Health), Quality Assurance and Control (QAC) tools were developed, like the ones described by Szklo & Nieto, 7 for the planning, execution and analysis of epidemiological studies.ELSA-Brasil is a cohort study that aims to follow up 15,000 participants, in six research centers, based on interviews and tests of varied complexities. These characteristics -large size, longitudinal nature, multicenter organization, measurements of distinct complexities -structured the strategic defi nition of the QAC system to be adopted.Experience in planning and conducting large longitudinal studies, especially from the 1950s onwards, has enabled the development of QAC tools to be used in cohort studies 8 and in randomized clinical trials. 4 The QAC system of Elsa-Brasil was based on this international experience, and necessary adaptations were performed by the Steering Committee and its Advisory Committees, founded on principles outlined by the QAC Committee.The present study aimed to describe the QAC actions in the ELSA-Brasil, presenting them in the sequence in which they were developed and indicating how and when key QAC decisions were adopted in the construction of the cohort and in its follow-up. QUALITY ASSURANCEQuality assurance activities in the ELSA are defi ned by the set of actions developed before the beginning of data collection, in order to ensure the quality desired for the study's results. They are:• development of the research protocol;• selection of research instruments to fulfi ll the objectives of the study, based on literature data;• development of t...