Statistical analysis
In this study, SPSS 23.0 was used for the statistical analysis of the data. All normal measurement data were expressed as mean ± standard deviation, and the independent normal and equal variance data of the two groups were compared with the t‐test of two independent samples. All the computing data were expressed as case numbers and percentages. The chi‐square test was used for comparison between the two groups, and the continuous correction chi‐square test was adopted when there was 1 < theoretical frequency (T) < 5. The test level α = 0.05 was taken in the statistical analysis.