Understanding the direct effect is essential for several reasons:
Intervention Evaluation: Identifying the direct effect helps in evaluating the true efficacy of public health interventions. For example, if a vaccine is found to reduce disease incidence, knowing the direct effect allows us to understand how much of this reduction is due to the vaccine itself, as opposed to other factors like changes in behavior. Policy Making: Policymakers rely on direct effect estimates to make informed decisions. Accurate assessment ensures that resources are allocated efficiently to interventions that have a substantial direct impact on health outcomes. Mechanistic Insights: By distinguishing between direct and indirect effects, researchers can gain insights into the biological or behavioral mechanisms of disease causation and progression.
