Statistical analysis
The data were analysed by Statistical Package for Social Sciences program (SPSS) software version 20. Descriptive statistics for numerical variables are presented as the mean and standard deviation, and those for qualitative variables are presented as numbers and percentages. One-way analysis of variance (ANOVA) was used to assess differences in quantitative variables between the three groups. The Chi-square test and Fisher’s exact were used to assess differences in qualitative variables between the three groups. A 