Temporal trend of COVID-19 incidence and mortality rates and their relationship with socioeconomic indicators in the state of Piauí, Brazil: an ecological study, 2020-2021

To analyze the temporal trend of COVID-19 incidence and mortality rates and their relationship with socioeconomic indicators. This was an ecological time series study of COVID-19 cases/deaths in municipalities in Piauí, Brazil, between March, 2020 and May, 2021. Prais-Winsten linear regression model and Spearman's correlation test were used. There were 271,228 cases and 5,888 deaths in the period. There was a rising trend in COVID-19 incidence rate, while the mortality trend was stable. The spatio-temporal analyses showed higher incidence/mortality in the second and fifth quarters of the period. There was no statistically significant correlation between COVID-19 and the Social Vulnerability Index (IVS). Significant correlations between the Municipal Human Development Index (IDHM) and COVID-19 incidence (p-value < 0.001) and mortality rates (p-value < 0.001) were found. There was a rising trend in COVID-19 incidence and stability in COVID-19 mortality. Correlation between the MHDI and these two indicators was moderate and weak, respectively, demanding public service management decisions aimed at improving the population's quality of life.