Reviews p 248 It seems that the whole world is suddenly talking about measuring the performance of health systems. Last month the World Health Organization published its findings from a comparative study of healthcare systems.1 This time it is the turn of the Department of Health in England, which last week published the results of the second round of performance indicators for 99 health authorities and 275 NHS hospital trusts.2 Unlike last year's figures, these data will inform and shape key aspects of the government's plan for the NHS, which will be published next week. The main message of the latest performance indicators is that health in England is continuing to improve. However, there is also compelling evidence of variation in health and healthcare performance between areas and between hospitals. For example, the proportion of patients waiting less than two hours to be admitted after attending an …