Using the right stats when discussing a treatment's dangers

August 1, 2004

The way a physician presents statistics on the risks and benefits of a specific medical intervention can have a profound effect on the decisions patients make concerning treatment.

Study participants presented with only relative risk figures were twice as likely to choose chemotherapy as those presented with absolute risk figures. When subjects were given statistics in four of the most common ways of presenting survival data—relative risk reduction, absolute risk reduction, absolute survival benefit, and number needed to treat—participants reported being confused and less able to make a decision at all.

The researchers concluded that the most effective and least confusing way of presenting data is to use absolute risk reduction and to explain the data using charts or other visual aids that help ensure that all patients make fully informed health-care decisions.

Hede K. When 50 percent is not the same as a coin toss: study examines decisions made based on statistics. J Natl Cancer Inst. 2004;96:737-738 and Chao C, Studts JL, Abell T, et al. Adjuvant chemotherapy for breast cancer: how presentation of recurrence risk influences decision-making. J Clin Oncol. 2003;21:4299-4305.