ObjectiveTo determine whether all grades of severity of postoperative adverse events are associated with prolonged length of stay in patients undergoing pulmonary cancer resection. MethodsThis was a retrospective cohort study of all patients who underwent pulmonary resection with curative intent for malignancy at The Ottawa Hospital, Division of Thoracic Surgery (January 2008 to July 2015). Postoperative adverse events were collected prospectively with the Thoracic Morbidity & Mortality System, based on the Clavien-Dindo severity classification. Patient demographics, comorbidities, preoperative investigations, cardiopulmonary assessment, pathologic staging, operative characteristics, and length of stay were retrospectively reviewed. Prolonged hospital stay was defined as >75th percentile for each procedure performed (wedge resection 6 days, segmentectomy 6 days, lobectomy 7 days, extended lobectomy 8 days, pneumonectomy 10 days). Univariable and multivariable logistic regression analyses were conducted to identify factors associated with prolonged hospital stay. ResultsOf 1041 patients, 579 (55.6%) were female, 610 (58.1%) were >65 years old, 232 (22.3%) experienced prolonged hospital stay, and 416 (40.0%) patients had ≥1 postoperative adverse event. Multivariable analyses identified significant (P < .05) factors associated with prolonged hospital stay to be (odds ratio; 95% confidence interval): lower diffusion capacity of the lung for carbon monoxide (0.99; 0.98-0.99), surgical approach: open thoracotomy (1.8; 1.3-2.5), and presence of any postoperative adverse event: Grade I (5.8; 3.3-10.2), Grade II (6.0; 4.0-8.9), Grade III (11.4; 7.0-18.7), and Grade IV (19.40; 7.1-55.18). ConclusionsLower diffusion capacity of the lung for carbon monoxide, open thoracotomy approach, and the development of any postoperative adverse event, including minor events that required no additional therapy, were factors associated with prolonged hospital stay.