On the international congress of neuropathic pain (NeuPsig) 2010 in Athens professor A. Moore from the Nuffield Department of Anaesthetics, University of Oxford, UK, put a cold and fishy eye on what is really known about the efficacy of drugs in neuropathic pain. In his talk he pointed out: “The great thing about being right is that you don’t have to change your mind so often” And Moore cited in the beginning of his talk Ioannides: “The trouble with evidence based medicine I that most of it is wrong.” (Ioannides PLOS medicine 2005 “Most published research findings are false.”)

Clinical relevant and significant is not always a desirable state...

He pointed out that increasingly attention is turning to whatconstitutes a clinically useful outcome and defines such an outcome asan outcome that is important for the patient, not just one that ismeasurable. Clinical trial outcomes indicates that not every patient benefits froma particular treatment, and that in many painful conditions most do notbenefit enough.

What the patient perceives as relevant is not always comparable to what has been measured during clinical trials. But if we succeed in treating pain, those patients whose pain isreduced significantly also benefit in a range of other ways - withimproved sleep, less depression, and improved quality of life. Good pain treatment therefore is the key.

He then discussed the question 'what is a significant pain benefit?From the clinical trial perspective a moderate effect can be defined as30% reduction in pain and a substantial effect can be defined as morethan 50% reduction from baseline scores. Patients when asked what they perceive as relevant see thisdifferently: a satisfactory reduction of pain is a reduction of painunder 3 points on the 11 point numerical rating scale (NRS). Thus, heshowed that clinical relevant reductions of 50%, as defined by trialarchitects, does not necessarily be in line with what a patientperceives as a clinical meaningful reduction, that is a NRS of 3 orless.

He than demonstrated this using a graphic. Patients who scoreat baseline a 8 and after therapy 4, being a clinical relevant changeaccording to the protocol, it would not be such a change for thepatient, who desires to reach a state of pain defined as less than 3 onthe NRS. According to the protocol such a patient is a responder but atthe same time the patient did not reach the desired state of score lessthan 3. On the other hand, a patient starting with 3,5 and ending on2,5, is according to the protocol a non-responder, although this painscore reaches a desired state.

source: A. Moore DRUG TREATMENTS FOR NPPs - LOOKING AT THE EVIDENCE WITH A COLD AND FISHY EYE  European Journal of Pain Supplements, Volume 4, Issue 1, May 2010, Page 46