Acute and chronic pain places a huge burden on our society. Approximately 10% of the population in Western countries report suffering from chronic pain, and both chronic and acute pain are responsible for high absenteeism in the workplace. It is therefore crucial that we have effective ways of treating pain. Unfortunately though, we have no objective measures of pain - no blood tests, no urine dipsticks. We have to rely on what the patient tells us. So how then do we know what are and what are not effective pain treatments? It is here that the principles of evidence-based medicine have been...