The identification and measurement of health - related spillovers in impact evaluations

This systematic review by Benjamin-Chung and colleagues examines the existing evidence on interventions associated with health-related spillover effects. It summarises common issues with design, analysis and reporting, and then make recommendations for future studies. The review is important because current methods to estimate such effects are not coherent across sectors. The review finds evidence of such spillover effects across several intervention types, including health and education programmes. Many different methods were used to estimate effects.  The authors recommend solutions for ensuring that future research includes health-related spillovers as an outcome. These recommendations should allow for greater comparability of spillover studies in future syntheses.