Sensitivity analysis for unmeasured confounding
Mediation methods are developed under strict no-unmeasured confounding
assumptions (22, 23). To examine the robustness of causal effects to
unmeasured confounders, we estimated the E-value (24, 25). The E-value
provides an estimate (on the excess risk scale) of the smallest excess
risk of the unmeasured confounder(s), beyond that accounted for the
adjusted confounders, to draw the observed excess toward the null. In
addition, the E-value provides an indication of the smallest excess risk
of the unmeasured confounder to move the lower 95% CI of the observed
excess risk to cross the null.
All analyses were conducted using SAS, version 9.4 (SAS Institute, Cary,
NC).