Statistical analysis
cholangitis
CHOLANGITIS
Sample size calculation was based on the incidence of cholangitis as the primary outcome. The incidence of cholangitis in RYHJ-C was supposed to be 7.7% according to the results of a previous study [Prospectively collected data were expressed as numbers and percentages for qualitative variables (which were compared by the Chi-square test) or as mean ± standard deviation for quantitative variables (which were tested by Mann– Whitney 