The Civil Registry in the first four months of the Covid-19 pandemic in Brazil: a comparative study between deaths by month of occurrence and by month of registration

Abstract The Civil Registry provides information on demographic studies on mortality, fertility and nuptiality. Questions have been raised about death registration when the causes of death are related to Covid-19. Notification may be delayed. Based on information provided by the Civil Registry of deaths, stratified by two groups - date of registration and date of occurrence - by Covid-19, this study compares these groups by city categories (capital, metropolitan region, interior), over March, April, May and June 2020, occurring in the first four months of the pandemic in Brazil. The magnitude and meaning of the differences in death records between the two groups were assessed. Graphs and linear regression analyses were used for comparisons. The findings indicate a different behavior of deaths per month of registration compared to deaths per month of occurrence between March and June. It is important to identify such a difference in behavior since, for the very short-term monitoring of the pandemic, deaths from registry data anticipate deaths whose records will still be adequately available by occurrence data. Such variation occurs mainly due to the systematic correction and updating of the information. As for the city categories, the biggest difference between deaths by month of occurrence and registration was observed for the municipalities in the interior, in line with the spread of the epidemic towards the interior in the month of May.