Adjusting the Number Needed to Treat

Abstract

The number needed to treat is a unique and cognitively useful summary measurement for the description of medical treatments. However, the original concept lacks the means to account for multiple benefits and harms or differences in the utilities or timings of patient outcomes. The authors describe an "adjusted" number needed to treat that allows for the inclusion of multiple harms and benefits, and also adjustments for the utilities and timings of these outcomes. This expanded version offers a richer description of medical outcomes, and may be utilized as an adjunct to traditional risk-benefit, cost-effectiveness, and de cision-analytic techniques. Key words: medical decision making; cost-effectiveness anal ysis ; decision analysis; risk-benefit analysis. (Med Decis Making 1993;13:247-252)