Scaling up in international health: what are the key issues?

We discuss four pertinent issues in scaling up the coverage of health interventions: the costs of scaling up coverage; constraints to scaling up; equity and quality concerns; and key service delivery issues when scaling up. We then review recent progress in scaling up the coverage of health interventions. This includes a considerable increase in the volume of aid, accompanied by numerous new health initiatives and financing mechanisms. There have also been improvements in health outcomes and some examples of successful large-scale programmes. Finally, we reflect on the importance of obtaining a better understanding of how to deliver priority health interventions at scale, the current emphasis on health system strengthening and the challenges of sustaining scaling up in the prevailing global economic environment.