Evidence based medicine is moving from relatively simple questions about a drug's safety and effectivenesss to thornier questions of relative clinical effectiveness and cost effectiveness, international experts agreed at a meeting last week. The experts, from the United States, Canada, the United Kingdom, and Germany, had assembled to discuss these issues with congressional and policy staff in Washington, DC.

“While there is a lot of data out there, unfortunately it is often very poor,” said Dr Peter Littlejohns, director of the UK's National Institute for Health and Clinical Excellence. …