Table 2 Description of mediation effects
From: Mediators of socioeconomic inequalities in preterm birth: a systematic review
Effect Measure | Description |
|---|---|
Total Effect | The overall effect of the exposure on an outcome: --For the difference method, this is the regression output for the exposure when not adjusted for the mediator. --For product of coefficients, this is the sum of direct and indirect effect |
Direct Effect | The effect of the exposure on an outcome when the intermediate variable is removed |
Indirect Effect | The effect of the exposure on an outcome through an intermediate variable |
Proportion Eliminated | How much of the total effect would be removed through action on the intermediate variable (setting the mediator to the same level for all pregnant women) [26]: --For the difference method, this is the difference between the total effect and regression output for the mediator-adjusted regression, divided by total effect (minus one if using exponentiated outputs) --For product of coefficients, this is the indirect effect divided by total effect [14] |