Click on image to view larger version.

Figure 1 Predicted probability of developing atrial fibrillation/atrial flutter (AF) by the point score. Circles = observed probability of post-coronary artery bypass graft (CABG) AF. Areas of the circles are proportional to the number of patients with each score value in the study population. Curve = predicted probability of post-CABG AF generated from a spline smooth of the logistic regression model based on point score. Vertical dash lines = cutoff of point scores of the three risk categories for AF.