# Introduction

- According to the reference
^{1}, "The E-value is the minimum strength of association, on the risk ratio scale, that an unmeasured confounder would need to have with both the treatment and outcome, conditional on the measured covariates, to explain away a treatmentâ€“outcome association." - Both the Stata command (evalue) and web E-value calculator implement the formula given by the table 1 and table 2 form the reference
^{1}. - You are encouraged to read comments
^{2,3}and tecniques^{4,5}about E-value - We will periodically update the reference list.