S3.1 Challenges and key issues in evaluation of public health interventions

Interest in evaluating the impact of large-scale public health interventions has been increasing globally over the past few years to inform effective use of public resources. Consequently some high-profile evaluations of complex public health interventions to improve population health in low- and middle-income countries have been reported recently. This increased, and desirable, focus on evaluations has helped bring attention to some major challenges that are encountered when attempting to assess the impact of large-scale public health interventions. These include the process of planning or commissioning of the evaluation, the design and analytical approaches that are both robust and feasible, and the interpretation and dissemination of findings. Examples will be used to illustrate these challenges. The key issues that need to be dealt with for improving evaluations of large-scale and complex public health interventions in low- and middle-income countries and better utilisation of the findings will be discussed.