Comparison of risk of major adverse cardiac event as a function of: (top) the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) risk calculator versus the Revised Cardiac Risk Index (RCRI); and (middle) the National Surgical Quality Improvement Program Myocardial Infarction or Cardiac Arrest (NSQIP MICA) calculator versus the RCRI; and (bottom) the ACS NSQIP risk calculator versus the NSQIP MICA risk calculator. The identity line represents perfect agreement between risk prediction tools. The difference between the identity line and the regression line visually demonstrates the departure from perfect agreement across risk prediction tools. Each point represents a single observation. ICC = intraclass correlation coefficient.