Construction of the endemic channel: methodological guide in Excel and RStudio

Abstract

Epidemiological surveillance is an essential function of public health, and among the tools used for monitoring endemic diseases, the endemic channel stands out as an instrument that allows comparing observed incidence against its historical behavior to identify unusual increases in case numbers. The objective of this article is to detail the steps for constructing the endemic channel using the geometric mean method. A methodological guide was developed with sequential procedures, integrating formal equations and automated templates in Excel 365 and RStudio, with the aim of facilitating an operational and reproducible application across different levels of surveillance and in resource-limited settings.