Measuring Social Inequalities in Health in the COVID-19 Pandemic in a Middle-Income Country: The IDS-COVID-19 Index

Background: The COVID-19 pandemic displayed different epidemiological patterns across Brazil. We aimed to develop, for the first time, an index for the whole Brazil to identify the role of social disparities in the distribution of the COVID-19 pandemic.Methods: It was an ecological study. We built the Social Disparities Index for COVID-19 (IDS-COVID-19) using administrative data at the municipal level to select indicators for three domains: socioeconomic, sociodemographic, and difficult-to-access health services. The index represents the average z-score values of each domain for five phases of the pandemic between February 2020 and July 2022. We performed a descriptive analysis of the relationship of IDS-COVID-19 and mortality rate due to COVID-19 in people aged 60 or more.Findings: During the pandemic, 57.7% (3,212/5,562) of the Brazilian municipalities had High (H)/Very High (VH) IDS-COVID-19. Of these, 69.1% (2,220) were in the North and Northeast, followed by the Southeast with 18.27% (587), the Central-West with 9.99% (321), and the South with 2.61% (84). Before vaccination, there was the highest mortality rate by COVID-19 in people aged 60 and over in federated units with higher proportion of municipalities classified in High/Very High inequality in health.Interpretation: The IDS-COVID-19 identified the municipalities with the greatest health inequality for COVID-19 and their relationship with the pandemic. This finding can be extended to guide actions related to the pandemic and other public health emergencies in low-middle income countries.Funding: This work was supported by the Bill & Melinda Gates Foundation and Minderoo through the Grand Challenges ICODA pilot initiative Management and Governance (Grant number 2021.0095). CIDACS/Fiocruz-Bahia was supported by grant OPP1142172 from the Bill & Melinda Gates Foundation/Ministry of Health of Brazil/CNPq (Call number 47/2014), the Wellcome Trust (202912/Z/16/Z) the Bill and Melinda Gates Foundation, NIHR Global Health Research Program (Award Reference 16/137/99) and Decentralized Executive Term from Ministry of Health process number 25000200517/2019-46. Declaration of Interest: The authors declare no conflict of interest regarding this work.