Number needed to treat: a method for determining analgesic effectiveness.

The number needed to treat (NNT) is regularly reported in systematic reviews concerning pain treatments. When used effectively, the NNT is a powerful tool for decision making. The NNT can allow clinicians to assess whether new treatments are applicable to their patient population as well as an individual patient. Clinicians who understand the statistical terms associated with the NNT are better equipped to make decisions regarding a specific treatment and NNT described in a trial. Many authors describe new ways to describe and utilize the NNT This paper reviews these new methods and reviews the statistical terms associated with the NNT, using specific examples from the pain literature. [ABSTRACT FROM AUTHOR]