The variables we collected include gender, age, therapeutic effects, treatments, CCs, admission condition, and followed up situation of the patients. Single-factor analysis and multiple linear regression method were used to select and group the variables.[10 (link)] Since the dependent variable (inpatient medical expenditure) is not subject to normal distribution (Z = 0.69, P < 0.001), Kruskal-Wallis test (nonparametric statistical analysis) was used in single-factor analysis, and multiple linear stepwise regression analysis was carried out after the conversion of hospitalization expense by square root data.[11 (link)] All the data and material collected were entered into Excel 2010 software for Microsoft (Microsoft Corporation, Washington, USA), and statistical analyses were performed using SPSS software version 14.0 (SPSS Inc., Chicago, IL, USA).