Data analysis
Data were analyzed using SPSS 20.0 for Windows. Basic information on participation was summarized using frequency, percentage, mean, and standard deviation. The homogeneity of the two groups was assessed by Fisher’s exact test, t-test, and a chi-squared test. A Shapiro–Wilk test was used to test for normal distribution of data. Paired t-tests were used to test the hypotheses. The Cronbach’s alpha coefficient and Kuder-Richardson 20 were used to test the reliability of the measurement tools.