In prescribing a medication, it is ideal to use "evidence-based medicine" (EBM) as the rationale for prescribing a particular medication. But EBM has its limitations since epidemiological data will not provide the needed information to treat an individual patient. To help correct this apparent deficiency, it is now common practice to employ a relatively new tool, the Number-Needed-To-Treat (NNT) to compare the effectiveness of different analgesic agents in different pain conditions. NNT represents the number of patients that must be treated to obtain one patient with at least 50% pain relief after correction for placebo responders.
NNT has the advantage of clinical applicability by showing how many patients need to be treated for one to benefit from the medication. It also differentiates between active treatment and controls.
The Swedish Council of Health reported the NNT for trigeminal neuralgia medications:
Swedish Council on Health Technology Assessment. Methods of Treating Chronic Pain: A Systematic Review [Internet]. Stockholm: Swedish Council on Health Technology Assessment (SBU); 2006 Oct. SBU Yellow Report No. 177/1+2. PMID: 28876750.