The role of health economics research in implementation research for health systems strengthening.

It has long been recognised that the health-related Millennium Development Goals cannot be achieved without strengthened health systems. This article presents the most recent World Health Organization framework for strengthening health systems and considers how health economics research can be used to measure achievements against each of the goals of the framework. Benefits to health systems strengthening of incorporating health economics tools into operational research are highlighted. Finally, health economic tools are placed within an impact assessment framework that facilitates the capture of health systems considerations in implementation research for innovations in tuberculosis diagnosis.