A case-mix model for monitoring of postoperative mortality after surgery for lung cancer.

BACKGROUND: Postoperative mortality (POM) after surgery for lung cancer has been proposed as a performance indicator. Information on the size of the risk and its prognostic factors is needed to serve as a reference standard. PATIENTS AND METHODS: Electronic records from the Rotterdam Cancer Registry (n=2337) and the Thames Cancer Registry (n=3772) were retrieved and analysed by sex, age, period, histology, region and extent of surgery. Multivariable logistic regression analysis was used to determine prognostic factors, to calculate odds ratios (OR) and to develop a case-mix model. RESULTS: POM was 4.2% (n=257) on average and increased with age from 1.7% for patients younger than 60 years up to 9.4% for octogenarians. After lobectomy, POM was 2.9% against 6.0% and 9.5% after pneumonectomy left and right, respectively. Multivariable analysis showed higher risk for men (OR=1.4) and lower risk for adenocarcinoma (OR=0.6). CONCLUSIONS: The final prediction model supports comparison and monitoring of POM rates for lung cancer. Only a limited number of risk factors need to be registered to allow adjustment for case-mix.