title: NNT, number needed to treat: does it have any real value?
abstract: Clinical trials usually use the relative risk (rate ratio or hazard ratio) to compare the effects of one treatment modality with others. However, the numbers needed to treat/harm (NNT/NNH) are sometimes used as another way of presenting an estimate of the effect of a medical intervention, pointing at the number of patients needed to be exposed over a certain period of time in order to achieve one beneficial or adverse event. For clinicians and patients, this is a very simple and clear tool to demonstrate the consequences of a specific intervention. Epidemiologists and statisticians are more cautious with interpretations of data of that sort. This article brings the relevant perspectives of a clinician, an epidemiologist and a statistician in regard to the value of NNT/NNH.
authors.affiliation: Department of Medicine T, Ichilov Medical Center, 6 Weizman Street, Tel-Aviv, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Pines
authors.forename: S
authors.initials: S
authors.lastname: Shapiro
authors.forename: S
authors.initials: S
authors.lastname: Suissa
mesh_terms: D004813:Epidemiology; D006801:Humans; D008593:Menopause; D061366:Numbers Needed To Treat; D013223:Statistics as Topic