Figure 2. Decision tree showing decision nodes (squares) and chance outcomes (circles). End branches are labeled with outcome states. The subtrees to which the decision tree refers are depicted in a separate figure for simplicity. Adapted from Mason JJ, Owens DK, Harris RA, Cooke JP, Hlatky MA. The role of coronary angiography and coronary revascularization before noncardiac vascular surgery. JAMA. 1995;273(24):1919–1925.