Improving health care systems, while containing cost pressures, is a key policy challenge in most OECD countries. The recent economic and financial crisis has weighed heavily on fiscal positions – with gross government debt projected to exceed 100% of GDP in the OECD area by 2011 – and reinforced the need to improve public spending efficiency. Public spending on health care is one of the largest government spending items, representing on average 6% of GDP. Furthermore, health care costs are escalating rapidly, driven by population ageing, rising relative prices and costly developments in medical technology. Public health care spending is projected to increase by 3.5 to 6 percentage points of GDP by 2050 in the OECD area. Against this background, exploiting efficiency gains will be crucial to meet rapidly growing health care demand, without putting the public finances on an unsustainable path.