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.