Correlation between perioperative outcomes and long-term survival for non-small lung cancer treated at major centers

Abstract

Background: The public is placing increased emphasis on specialty specific rankings, thereby affecting patients' choices of clinical care programs. In the spirit of transparency, public reporting initiatives are underway or being considered by various surgical specialties whose databases rank programs based on short-term outcomes. Of concern, short-term risk avoidance excludes important comparative cases from surgical database participation and may adversely affect overall long-term oncologic treatment team results. To assess the validity of comparing short-term perioperative and long-term survival outcomes of all patients treated at major centers, we studied the correlations between these variables.

Methods: The National Cancer Database was queried for patients diagnosed with non-small cell lung carcinoma (NSCLC) between 2008 and 2012, yielding 5-year follow-up data for all patients at centers treating at least 100 patients annually. Mortality (30- and 90-day), unplanned 30-day readmissions, and hospital length of stay were modeled using logistic regression with sex, race, age, Charlson-Deyo combined comorbidity, extent of surgery, income, insurance status, histology, grade, and analytic stage as predictors, all with 2-way interaction terms. The differences between the predicted rates and observed rates were calculated for each short-term outcome, and the average of these was used to create a short-term metric (STM). A similar approach was used to create a long-term metric (LTM) that used overall survival as a single dependent variable. Centers were ranked into deciles based on these metrics. Visual plotting as well as correlation coefficients were used to judge correlation between STM and LTM.

Results: A total of 298,175 patients from 541 centers were included in this analysis, of whom 102,860 underwent surgical resection for NSCLC. The correlation between STM and LTM was negative using parametric estimates (Pearson correlation coefficient = -0.09 [P = .03] and -0.22 [P < .01]) and nonparametric estimates (Spearman rank correlation coefficient = -0.09 [P = .02] and -0.22 [P < .01]) for squamous cell carcinoma and adenocarcinoma, respectively.

Conclusions: Short-term perioperative outcome rankings correlate poorly with long-term survival outcome rankings when cancer treatment centers are compared. Factors explaining this discrepancy merit further study. Rankings based on short-term outcomes alone may be incomplete for public reporting.

Keywords: long-term outcomes; non–small cell lung cancer; overall survival; perioperative outcomes.