Association between length of stay and postoperative survival in patients with lung cancer: a propensity score matching analysis based on National Cancer Database.

BACKGROUND

Postoperative complications tend to result in prolonged hospitalization. The aim of this study was to investigate whether prolonged postoperative length of stay (LOS) can predict patient survival, particularly long-term survival.

METHODS

All patients undergoing lung cancer surgery between 2004 and 2015 were identified in the National Cancer Database (NCDB). The highest quintile of LOS (more than 8 days) was defined as prolonged length of stay (PLOS). We performed 1:1 propensity score matching (PSM) between the groups with and without PLOS (Non-PLOS). Excluding confounding factors, postoperative LOS was used as a surrogate for postoperative complications. Kaplan-Meier and Cox proportional hazards survival analyses were performed to analyze survival.

RESULTS

A total of 88,007 patients were identified. After matching, 18,585 patients were enrolled in the PLOS and Non-PLOS groups, respectively. Before and after matching, 30-day rehospitalization rate and 90-day mortality in the PLOS group were significantly higher than they were in the Non-PLOS group (P<0.001), indicating a potential worse short-term postoperative survival. After matching, the median survival of the PLOS group was significantly lower than that of the Non-PLOS group (53.2 63.5 months, P<0.0001). Multivariable analysis revealed that PLOS is independent negative predictor of overall survival [OS; hazard ratio (HR) =1.263, 95% confidence interval (CI): 1.227 to 1.301, P<0.001]. In addition, age (<70 or ≥70), gender, race, income, year of diagnosis, surgery type, pathological stage, and neoadjuvant therapy also were independent prognostic factors of postoperative survival for patients with lung cancer (all P<0.001).

CONCLUSIONS

Postoperative LOS could be taken as the quantitative indicator of postoperative complications of lung cancer in NCDB. In this study, PLOS predicted worse short-term and long-term survival independent of other factors. Avoiding PLOS could be considered to benefit patient survival after lung cancer surgery.