Predictors of Prolonged Length of Stay after Lobectomy for Lung Cancer: A Society of Thoracic Surgeons General Thoracic Surgery Database Risk-Adjustment Model

Background: Few reliable estimations of operative risk exist for lung cancer patients undergoing lobectomy. This study identified risk factors associated with prolonged length of hospital stay (PLOS) after lobectomy for lung cancer as a surrogate for perioperative morbid events. Methods: The Society of Thoracic Surgeons (STS) General Thoracic Surgery Database was queried for patients with lobectomy for lung cancer. A model of preoperative risk factors was developed by multivariate stepwise logistic regression setting the threshold for PLOS at 14 days. Morbidity was measured as postoperative events as defined in the STS database. Risk-adjusted results were reported to participating sites. Results: From January 2002 to June 2006, 4979 lobectomies were performed for lung cancer at 56 STS sites, and 351 (7%) had a PLOS. They had more postoperative events than patients without PLOS (3.4 vs 1.2; p < 0.0001). Patients with PLOS also had higher mortality than those with normal LOS, at 10.8% (38 of 351) vs 0.7% (33 of 4628; p < 0.0001). Significant predictors of PLOS included age per 10 years (odds ratio [OR], 1.30, p < 0.001), Zubrod score (OR, 1.51; p < 0.001), male sex (OR, 1.45; p = 0.002), American Society of Anesthesiology score (OR, 1.54; p < 0.001), insulin-dependent diabetes (OR. 1.71; p = 0.037), renal dysfunction (OR, 1.79; p = 0.004), induction therapy (OR, 1.65; p = 0.001), percentage predicted forced expiratory volume in 1 second in 10% increments (OR, 0.88; p < 0.001), and smoking (OR, 1.33; p = 0.095). After risk adjustment, twofold interhospital variability existed in PLOS among STS sites. Conclusions: We identified significant predictors of PLOS, a surrogate morbidity marker after lobectomy for lung cancer. This model may be used to provide meaningful risk-adjusted outcome comparisons to STS sites for quality improvement purposes.