Statistical analysis
The normality of the distribution, including the average values of the indicators, was assessed using the Kolmogorov–Smirnov test, and the homogeneity of variance was tested using Levine’s test. All data in this study fitted normal distribution and were expressed as mean ± standard deviation. The change in the average value prior to and following intervention was assessed using the paired-sample SPSS19.0 (IBM, NY, USA) was used to perform statistical analysis. 