Background: So far, little is known of how the sociodemographic characteristics of populations affect the risk of SARS-CoV-2 infection. The regional sociodemographic heterogeneity of the Portuguese territory and the heterogeneity of CoVID-19 incidence along the country create an opportunity to uncover the relationship between these characteristics and CoVID-19 incidence. Methods: We have gathered data on the sociodemographic characteristics and CoVID-19 incidence in the 278 municipalities of the Portuguese mainland territory and evaluated the relationships between them, in both univariate and multivariate analysis. The rank correlation Spearman´s coefficient was used to identify variables significantly associated with CoVID-19 incidence in univariate analysis. After exclusion of those highly correlated with each other, they were included in a stepwise multiple regression model to identify those independently associated with CoVID-19 incidence. Results: The municipalities’ sociodemographic characteristics independently associated with an increased risk of SARS-CoV-2 infection are the population density, the size of households, the number of employees per non-financial company, and the proximity to the great metropolitan areas. On the other hand, the percentage of primary sector employees is independently associated with a decreased risk of SARS-CoV-2 infection. Conclusions: The study results, by allowing the identification of regional sociodemographic characteristics associated with higher risk of infection, might help health authorities to make a more rational allocation of available resources and to more effectively combat the pandemic.
Antonio Ferreira, Antonio Oliveira-e-Silva and Paulo Bettencourt