Figure 2.

Nomogram predicting postoperative urinary retention (POUR) in general thoracic surgery patients. The total points for a 65-year-old male patient who had a preoperative creatinine level of 3.0 mg/dL, history of preoperative chronic obstructive pulmonary disease (COPD), underwent lobectomy, and had postoperative patient-controlled analgesia (PCA) use, can be calculated as 65 (age) + 32 (male) + 30 (creatinine × 10) + 14 (preoperative COPD) + 34 (lobectomy) + 33 (postoperative PCA) = 208 approximately, with a predicted probability of POUR (indicated by the line of risk of event) around 0.8.