Understanding Risk: A Randomized Controlled Trial of Communicating Contraceptive Effectiveness

Markus Steiner, Family Health International
Rosalie Dominik, Family Health International
Sandy Dalebout, Family Health International
Sean Condon, Family Health International

Accurately communicating risk to patients poses challenges. We randomized 433 reproductive aged women to one of three tables presenting contraceptive effectiveness (pregnancy rates, pregnancy categories, or a combination of rates and categories). Before looking at the tables, about half the women knew that pills are more effective than condoms (57%) and that hormone shots are more effective than pills (48%). While the two tables containing numbers increased participants’ knowledge about the two key comparisons (pills vs. condoms and pills vs. hormone shots) by 15-20 percentage points, the table with only categories increased participants knowledge by about 30 percentage points (p<0.05). Moreover, participants assigned to the table with only categories were slightly more likely to report that their table provided enough information and was significantly easier to understand (p < 0.01). A combination of categories and risk ranges may provide the most accurate understanding of both relative and absolute pregnancy risk.