Statistical analysis
Categorical variables were described as frequency rates and percentages, and continuous variables were described using mean, median, and interquartile range (IQR) or standard deviation (SD) values. Means for continuous variables were compared using the Mann-Whitney test. Proportions for categorical variables were compared using the χ2 test, and the Fisher exact test was used when the data were limited. To calculate the quantitative measure of effect size, the Cohen’s d index was measured for the qualitative outcomes of the two methods using mean and standard deviation. The Cohen’s d index of less than or equal to 0.2 was considered as a small size effect, whereas 0.5 and 0.8 results were considered as the medium and large size effects, respectively. All statistical analyses were performed using SPSS (Statistical Package for the Social Sciences), version 16.0 software (SPSS Inc). A P-value of lower than 0.05 in the multivariate analysis was considered significant.