Evidence based medicine has been defined as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.”1 Few areas of medical practice have felt the effects of this movement more clearly than prescribing. Until recently doctors could prescribe medicines without worrying that their choices might be judged against evidence accumulated in the world's literature. Now, prescribers are increasingly expected to back up their decisions with evidence.2 Enthusiasm for evidence based prescribing is welcome and should lead to safer and more effective use of medicines. But it also poses some real problems for prescribers.

Reliable information to underpin everyday prescribing decisions at the point of prescription is hard to find. One solution is to provide modern information technology systems in the consulting room or at the bedside.3 But even these may deliver too much unfiltered information including some original research, some guidance derived from research, …