Searching & Browsing: Databases Searched

Essential Evidence Plus searches 7 different databases. Select one of the databases listed below for a description of the database and its purpose, as well as an example of how it can be used in the clinical decision process.

These additional resources are also available:


Number Needed To Treat (NNT)

A statistic that conveys how many patients need to be treated with one intervention, instead of another, for one additional patient to receive benefit

Purpose: To help compare the likelihood of benefit (or harm) among several potential therapeutic options, since most interventions don’t benefit (or harm) 100% of the patients treated

Example of use: In the treatment of class I or II heart failure, treatment of 100 patients with an ACE inhibitor will prevent one additional death. In more severe disease (class IV), only six patients require treatment for an additional death to be prevented.

Detailed Description: The NNT gives us a better understanding of the relative benefit of treatment as compared with other statistics such as relative risk reduction. By knowing the NNT, clinicians and patients can determine whether a particular treatment is "worth it."