Effectiveness of a multicomponent intervention to face the COVID-19 pandemic in Rio de Janeiro's favelas: difference-in-differences analysis.

Introduction: Few community-based interventions addressing the transmission control and clinical management of COVID-19 cases have been reported, especially in poor urban communities from low-income and middle-income countries. Here, we analyse the impact of a multicomponent intervention that combines community engagement, mobile surveillance, massive testing and telehealth on COVID-19 cases detection and mortality rates in a large vulnerable community () in Rio de Janeiro, Brazil.

Methods: We performed a difference-in-differences (DID) analysis to estimate the impact of the multicomponent intervention in before (March-August 2020) and after the intervention (September 2020 to April 2021), compared with equivalent local vulnerable communities.