Indirect effects are essential for several reasons: 1. Comprehensive Evaluation: They help in understanding the full impact of public health interventions. For instance, a smoking cessation program not only benefits participants by reducing their risk of lung cancer but also reduces secondhand smoke exposure to others. 2. Policy Making: Policymakers can make better-informed decisions when they consider both direct and indirect effects. For example, investing in sanitation infrastructure has direct health benefits by reducing disease transmission and indirect benefits by improving overall community health and productivity. 3. Cost-Effectiveness Analysis: Including indirect effects in cost-effectiveness analysis provides a more accurate estimate of the value of interventions.
