Objective: To investigate the efficiency of original diseases by the Charlson weighted index of comorbidities (WIC) in predicting 28-day mortality in patients with critical illnesses in intensive care unit (ICU).
Methods: A single-center retrospective analysis of clinical data of 406 patients admitted between January 2009 and October 2011 to Shanghai Changzheng Hospital was conducted. The patients were divided into non-survivor group (n=104) and survivor group (n=302) according to 28-day outcome. The data were recorded, and the WIC and the acute physiology and chronic health evaluation II (APACHEII) score were calculated. Logistic regression analysis was used to determine the independent predictors for 28-day mortality.
Results: Compared with survivors, the average age, WIC and APACHEII scores, severe sepsis, pneumonia, and multiple injuries were higher in non-survivors. The univariate analysis showed that age, the WIC score, APACHEII score, pneumonia, multiple injuries and severe sepsis were related with patients' 28-day prognosis. The multivariate logistic regression revealed that 28-day prognosis depended significantly on WIC score [odds ratio (OR)=1.538, 95% confidence interval (95%CI) 1.265 - 1.869, P=0.000], APACHEII score (OR=1.193, 95%CI 1.137 - 1.252, P=0.000), pneumonia (OR=0.546, 95%CI 0.304 - 0.982, P=0.043), and severe sepsis (OR=0.178, 95%CI 0.098 - 0.323, P=0.000). The area under the receiver operating characteristics curve (ROC curve) in predicting mortality was 0.657 (0.592 - 0.722) for the WIC score, 0.790 (0.739 - 0.841) for APACHEII score and 0.821 (0.772 - 0.869) for their combination.
Conclusion: The WIC scoring system can be a good evaluation method for 28-day prognosis in ICU patients.