Figure 1. Sensitivity analysis of the effect of gender and weight on the risk of adverse events for patients undergoing Roux-en-Y gastric bypass surgery. The probability of adverse events is represented on the ordinate and weight on the axis of the graph. For a 200-lb women, the risk of developing complications is slightly less than 4% and rises to 12% at 900 lb. The complication risk is higher for men at each weight and rises more steeply for men compared to women as weight increases. A 200-lb man has a 6.5% risk of complications that increases to 20% at 900 lb.