What's new about evidence-based medicine? Medical practice has been based upon scientific evidence for some time, although the standards of evidence we require before using a treatment are becoming more stringent. EBM places more emphasis on evidence from randomised controlled trials (RCTs) than on clinical anecdote, but the notion that RCTs are the best evidence on the effectiveness of interventions has been around for nearly SO years. There is more emphasis now on systematic reviews and although they are not a new idea, their widespread acceptance has been a relatively recent phenomenon within medicine.