Metrics and Statistical Methods
The Mortality Information System (acronym in Portuguese: SIM) was implemented in 1975 and was the first nationwide epidemiological information system of the Ministry of Health.
The basic document of SIM is the Death Certificate, which is supposed to be filled out by a doctor. The doctor who assisted the person who died is primarily responsible for the document. However, if the assistant physician is not available, a substitute doctor, the doctor from the Death Verification Service — for death from natural causes — and the coroner from the Medical Examiner’s Office — for deaths from external causes must take charge.[1,2,3]
SIM is one of the main tools for monitoring mortality statistics in Brazil, as all Brazilian cities must register their deaths, which leads to around 1.3 million death registrations per year.
Over the years, SIM has had its quality improved, such as increased coverage of death registrations in all Brazilian states, from 86% in 2000 to 98% in 2017, although some Northern and Northeastern states still have coverages lower than 95%.[1,3] Another indicator that shows the improved quality of SIM data is the amount of ill-defined causes of deaths, which also dropped but, when each region is analyzed individually, it is still high. Because of this, health situation analyses conducted with mortality data should be performed using correction methodologies capable of minimizing the bias caused by ill-defined causes, garbage codes (CG) and the underreporting of deaths.
The Cardiovascular Statistics present the SIM data, according to the methodology proposed by Malta et al., (2020), using aged-standardized population to calculate rates, and applying corrections such as: a) in the numerator, the deaths from the chapter of cardiovascular diseases (I00-I99) with correction of underreporting and proportional redistribution of ill-defined causes, proportionally between the groups of cardiovascular causes and other causes, in addition to the proportional redistribution of deaths with no information regarding age and sex. b) The most updated population estimates generated by IBGE are used in the denominator.
Figure 1 — Summary of SIM data for estimates of cardiovascular diseases.
In 2020, Cardiovascular Statistics used GBD 2017 data for Brazil for international comparison. GBD uses SIM data and applies a complex standardized methodology to all countries in the study containing corrections for underreporting of deaths, redistribution of garbage codes (ill-defined and nonspecific causes that should not be considered as the ultimate root cause of death for not having importance for public health actions) and the GBD 2017 world population. Thus, GBD and SIM estimates, with the corrections made, may differ.
For the next editions, new SIM correction methodologies will be applied for comparison with the GBD estimates. In the current edition, due to difficulties in redistributing SIM deaths into more disaggregated levels of causes of deaths, it was decided to present the GBD 2017 estimates.
Malta DC, Teixeira, RA, Oliveira, GMM, Ribeiro AP. Mortality due to Cardiovascular Diseases according to Mortality Information System and estimates of Global burden of Diseases study, Brazil, 2000 to 2017. Arquivos Brasileiro de Cardiologia, 2020.
Brasil. Ministério da Saúde. Departamento de Informática do SUS – DATASUS. Informações de Saúde, Epidemiológicas e Morbidade: banco de dados. Disponível em: Acesso em: 12 fev. 2018.
Brasil. Ministério da Saúde. Saúde Brasil 2018 uma análise de situação de saúde e das doenças e agravos crônicos: desafios e perspectivas. Brasília: Ministério da Saúde, 2019. 424 p.
Instituto Brasileiro de Geografia e Estatística. Projeção da População Brasil e Unidades da Federação. Revisão 2018. 2ª Revisão.; Rio de Janeiro 2018.
GBD 2016 Causes of Death Collaborators.. Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. Volume 392, Issue10159, P1736-1788, NOVEMBER 10, 2018.