Age-adjusted Charlson comorbidity index score as predictor of survival of patients with digestive system cancer who have undergone surgical resection

// Yaohua Tian 1 , Zhong Jian 2 , Beibei Xu 3 and Hui Liu 3, 4 1 Department of Epidemiology and Biostatistics, School of Public Health, Peking University, 100083 Beijing, China 2 Hospital Administration Department, Peking University, 100083 Beijing, China 3 Medical Informatics Center, Peking University, 100083 Beijing, China 4 National Healthcare Data Center, Affiliated to National Center for Medical Service Administration, 100083 Beijing, China Correspondence to: Hui Liu, email: ymauil@bjmu.edu.cn Keywords: digestive system cancer, surgical resection, comorbidity, postoperative mortality, surgery Received: March 24, 2017 Accepted: May 23, 2017 Published: June 07, 2017 ABSTRACT Comorbidities have considerable effects on survival outcomes. The primary objective of this retrospective study was to examine the association between age-adjusted Charlson comorbidity index (ACCI) score and postoperative in-hospital mortality in patients with digestive system cancer who have undergone surgical resection of their cancers. Using electronic hospitalization summary reports, we identified 315,464 patients who had undergone surgery for digestive system cancer in top-rank (Grade 3A) hospitals in China between 2013 and 2015. The Cox proportional hazard regression model was applied to evaluate the effect of ACCI score on postoperative mortality, with adjustments for sex, type of resection, anesthesia methods, and caseload of each healthcare institution. The postoperative in-hospital mortality rate in the study cohort was 1.2% (3,631/315,464). ACCI score had a positive graded association with the risk of postoperative in-hospital mortality for all cancer subtypes. The adjusted HRs for postoperative in-hospital mortality scores ≥ 6 for esophagus, stomach, colorectum, pancreas, and liver and gallbladder cancer were 2.05 (95% CI: 1.45–2.92), 2.00 (95% CI: 1.60–2.49), 2.54 (95% CI: 2.02–3.21), 2.58 (95% CI: 1.68–3.97), and 4.57 (95% CI: 3.37–6.20), respectively, compared to scores of 0–1. These findings suggested that a high ACCI score is an independent predictor of postoperative in-hospital mortality in Chinese patients with digestive system cancer who have undergone surgical resection.