The challenges of using cross-national comparisons of efficiency to inform health policy

Many comparative efficiency metrics focus on scrutinising the operation of specific parts of a single health system. This article reviews the key issues involved in international comparisons of various aspects of efficiency. It examines data sources and analytic techniques used to create comparative indicators, and discusses approaches to interpreting variations. It also highlights key challenges and promising new initiatives, such as the consistent use of international definitions and technical developments, such as data linkages, which hold the potential to enhance work in this area.