# Sociodemographic inequalities in the incidence of COVID-19 in National Household Sample Survey cohort, Brazil, 2020

## TL;DR

This study examines how sociodemographic factors in Brazil influenced the incidence of COVID-19 from May to November 2020.

## Contribution

The study provides new insights into how social inequalities are linked to the spread of COVID-19 in Brazil.

## Key findings

- Higher incidence of COVID-19 was observed in the North region, females, urban residents, and individuals with black skin color.
- New positive tests were more frequent among individuals with less education and healthcare workers.
- The cumulative incidence of cases was 2.4%, while positive tests reached 27.1% in the tested cohort.

## Abstract

To verify the association between sociodemographic factors and the time until the occurrence of new cases of COVID-19 and positive tests for SARS-CoV-2 in Brazil, during the period from May to November 2020, based on a cohort of Brazilians participating in the COVID-19 National Household Sample Survey.

A concurrent and closed cohort was created using monthly data from the PNAD COVID-19, carried out via telephone survey. A new case was defined based on the report of the occurrence of a flu-like syndrome, associated with loss of smell or taste; and positivity was defined based on the report of a positive test, among those who reported having been tested. Cox regression models were applied to verify associations. The analyzes took into account sample weighting, calibrated for age, gender and education distribution.

The cumulative incidence of cases in the overall fixed cohort was 2.4%, while that of positive tests in the fixed tested cohort was 27.1%. Higher incidences were observed in the North region, in females, in residents of urban areas and in individuals with black skin color. New positive tests occurred more frequently in individuals with less education and healthcare workers.

The importance of prospective national surveys is highlighted, contributing to detailed analyzes of social inequalities in reports focused on public health policies.