Figure 4.
“Predicting Risk of Complications in Older Patients with Gallstones,” PREOP-Gallstones model nomogram. To use the nomogram, a vertical line is drawn from each factor to the corresponding position on the “Points” line. Once the points are tabulated for each factor, the points are then added. A line is drawn from this position on the “Points” line to the “Emergent Visit Probability” lines to determine a patient’s 12-month and 24-month risk for developing emergent gallstone-related complications.