This study was undertaken to determine factors associated with in-hospital mortality among patients after general thoracic surgery and to construct a risk model.
Methods
Data from a nationally representative thoracic surgery database were collected prospectively between June 2002 and July 2005. Logistic regression analysis was used to predict the risk of in-hospital death. A risk model was developed with a training set of data (two thirds of patients) and validated on an independent test set (one third of patients). Model fit was assessed by the Hosmer–Lemeshow test; predictive accuracy was assessed by the c-index.
Results
Of the 15,183 original patients, 338 (2.2%) died during the same hospital admission. Within the data used to develop the model, these factors were found to be significantly associated with the occurrence of in-hospital death in a multivariate analysis: age, sex, dyspnea score, American Society of Anesthesiologists score, performance status classification, priority of surgery, diagnosis group, procedure class, and comorbid disease. The model was reliable (Hosmer–Lemeshow test 3.22; P = .92) and accurate, with a c-index of 0.85 (95% confidence interval 0.83-0.87) for the training set and 0.86 (95% confidence interval 0.83-0.89) for the test set of data. The correlation between the expected and observed number of deaths was 0.99.
Conclusions
The validated multivariate model Thoracoscore, described in this report for risk of in-hospital death among adult patients after general thoracic surgery was developed with national data, uses only 9 variables, and has good performance characteristics. It appears to be a valid clinical tool for predicting the risk of death.