Statistics and analysis
Continuous variables were presented as mean (SD) or median (interquartile range) according to the distribution of the data. Categorical variables were presented as absolute frequencies and percentages. The chi-square test was used to compare qualitative variables. Continuous variables were analyzed using the Student Intention-to-treat (ITT) and PP analyses were performed. Patients who were successfully contacted were included in the PP analysis. Relative risk (RR) with CIs was calculated for efficiency evaluation.Statistical significance was set at 