In all 1-way sensitivity analyses (A–D), the x-axis displays the parameter for which sensitivity analysis is being performed and the y-axis represents quality-adjusted life-years (QALYs). In all 2-way sensitivity analyses (E and F), the x-axis represents the proportion of initial strokes due to intracerebral hemorrhage (ICH) and the y-axis represents a relative risk (RR) associated with aspirin in patients with prior ICH. In 1-way sensitivity analyses, the threshold at which the preferred strategy changes is marked by a vertical dashed line; aspirin treatment is preferred to no treatment to the left of this threshold value. In 2-way sensitivity analyses, the region favoring aspirin treatment is shaded blue and the region favoring no treatment is shaded red. In A and B, the base case proportion of strokes due to ICH (34%) is denoted by an arrow. In C and D, the base case value for the RR is denoted by a closed circle and its 95% confidence interval (CI) by a horizontal line. In E and F, the intersection of the base case value for proportion of initial strokes due to ICH and the RR is indicated by an asterisk, and dashed lines denote the 95% CIs of the RRs. (A) One-way sensitivity analysis of the proportion of initial strokes due to ICH. (B) One-way sensitivity analysis of age at time of first stroke. (C) One-way sensitivity analysis of the RR of recurrent ICH associated with aspirin after initial ICH. (D) One-way sensitivity analysis of the RR of acute mortality associated with aspirin if a patient has an ICH while on aspirin. (E) Two-way sensitivity analysis of the RR of recurrent ICH associated with aspirin and proportion of initial strokes due to ICH. (F) Two-way sensitivity analysis of the RR of acute mortality associated with aspirin if a patient has an ICH while on aspirin and proportion of initial strokes due to ICH.