Using and Interpreting Adjusted NNT Measures in Biomedical Research
Ralf Bender1, 2, *
Identifiers and Pagination:Year: 2010
First Page: 72
Last Page: 76
Publisher ID: TODENTJ-4-72
Article History:Received Date: 25/9/2009
Revision Received Date: 14/10/2009
Acceptance Date: 14/10/2009
Electronic publication date: 16/7/2010
Collection year: 2010
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The number needed to treat (NNT) is a popular effect measure to present study results in biomedical research. NNTs were originally proposed to describe the absolute effect of a new treatment compared with a standard treatment or placebo in randomized controlled trials (RCTs) with binary outcome. The concept of the NNT measure has been applied to a number of other research areas involving the development of related measures and more sophisticated techniques to calculate and interpret NNT measures in biomedical research. In epidemiology and public health research an adequate adjustment for covariates is usually required leading to the application of adjusted NNT measures. An overview of the recent developments regarding adjustment of NNT measures is given. The use and interpretation of adjusted NNT measures is illustrated by means of examples from dentistry research.