Abstract: Objective: To investigate the application value of Charlson's weighted index of comorbidities(WIC) in predicting the hospitalisation observation time of emergency patients.Methods: The clinical data of 3 353 emergency hospitalisation patients were retrospectively analyzed,and divided into the group A(2 239 cases,hospitalisation time ≥ 72 h) and group B(1 114 cases,hospitalisation time <72 h).The factors influencing hospitalisation time of patients were analyzed using logistic regression,and the related factors included the patient's age,sex,living condition,underlying disease,disease diagnosis,APACHEⅡ score,and WIC score.The predictive value of WIC scores in the observation time of patients was assessed by receiver operating characteristics(ROC) curve.Results: Among 3 353 patients,299(8.9%) cases with urinary and endocrine system diseases,522(15.6%) cases with digestive system diseases,838(25.0%) with circulatory and nervous diseases,1 356(40.4%) cases with respiratory disease and 338(10.1%) cases with other causes disease were found.The scores of APACHEⅡand WIC in group A were higher than those in group B(P<0.01).The age,living nursing-home,APACHEⅡ score and WIC score could affect the hospitalisation time of patients(P<0.01).The multivariable logistic regression analysis showed that the age,living nursing-home,APACHEⅡ score and WIC score did not exist the collinearity relation,and were the independently related factors of influencing the hospitalisation time of patients(P<0.01).The area under the ROC curve of APACHEⅡ score was 0.796,the WIC score was 0.691,and the area under the ROC curve of APACHEⅡ score combined with WIC score was 0.892.Conclusions: The WIC scoring system based on the underlying disease can be used to predict the hospitalisation observation time in emergency patients.