Statistical analysis
The sample size was calculated by power analysis(α= 0.05 and 90% power), using the reduction of L-K score from our preliminary findings in a pilot study. SPSS v25.0 (IBM SPSS, Armonk, NY) and GraphPad Prism v8.0(GraphPad Inc, USA) were used for statistical analysis. Continuous data in accordance with the normal distribution were expressed as mean and standard deviation(SD) and analyzed by one-way ANOVA, while data with non-normal distribution were expressed as median and quartile rangetested by Kruskal-Wallis test. Pearson chi-square test was used to classify the data. P<0.05 was considered to be statistically significant.