The Use of the Number Needed to Treat (NNT) in Randomized Clinical Trials in Psychological Treatment
Article first published online: 10 MAR 2010
© 2010 American Psychological Association. Published by Wiley Periodicals, Inc., on behalf of the American Psychological Association
Clinical Psychology: Science and Practice
Volume 17, Issue 1, pages 41–47, March 2010
How to Cite
Shearer-Underhill, C. and Marker, C. (2010), The Use of the Number Needed to Treat (NNT) in Randomized Clinical Trials in Psychological Treatment. Clinical Psychology: Science and Practice, 17: 41–47. doi: 10.1111/j.1468-2850.2009.01191.x
- Issue published online: 10 MAR 2010
- Article first published online: 10 MAR 2010
- Received March 6, 2009; accepted April 22, 2009.
- absolute risk reduction;
- effect size;
[Clin Psychol Sci Prac 17: 41–47, 2010]
There are many psychological treatments available for clinicians to implement with their clients, with numerous reports of which works best for whom. Clients have access to information regarding interventions and can benefit from easy-to-understand, yet powerful explanations of the results of treatment evaluations. The number needed to treat (NNT) is a potentially useful statistic, although it is highly underreported. A review of the Journal of Consulting and Clinical Psychology between 2000 and 2008 found that, of the 100 articles reviewed, four reported the NNT. Despite the need for powerful and intelligible statistics, behavioral scientists have yet to adopt and report the NNT in their results.