The age-adjusted Charlson comorbidity index is a better predictor of survival in operated lung cancer patients than the Charlson and Elixhauser comorbidity indices.

Abstract

To compare the prognostic performance between different comorbidity assessments of survival in patients with operated lung cancer. A total of 4508 lung cancer patients treated by surgery between 2003 and 2012 were identified through Taiwan's National Health Insurance Research Database. Information on pre-existing comorbidities prior to the cancer diagnosis was obtained and adapted to the Charlson comorbidity index, age-adjusted Charlson comorbidity index (ACCI) and Elixhauser comorbidity index scores. The influence on survival was analysed using a Cox proportional hazard model. The discriminatory ability of the comorbidity indices were evaluated using Akaike information criterion and Harrell's C-statistic. The mean age of the study cohort was 64.95 ± 11.15 years, and 56.28% of the patients were male. The median follow-up time was 2.59 years, and the 3-year overall survival was 73.94%. Among these patients, 2134 (47.3%) patients received adjuvant therapy. The Charlson comorbidity index and ACCI scores correlated well with survival and higher scores were associated with an increased 3-year mortality risk (hazard ratio = 1.21, 95% confidence interval = 1.03-1.42 and hazard ratio = 1.43, 95% confidence interval = 1.08-1.90, respectively) in multivariate analysis. The ACCI scores provided better discriminatory ability with a smaller Akaike information criterion and greater Harrell's C-statistic for 3-year overall survival compared to the Charlson comorbidity index or Elixhauser comorbidity index scores. The operated lung cancer patients with severe comorbidities were associated with worse survival. The ACCI appears to be a more appropriate prognostic indicator and should be considered for use in clinical practice.