Statistical analysis:
Data were analyzed by using version 26 of SPSS software. The analysis includes basic descriptive statistics (frequencies and percentages), and Chi-square test. Chi-square test was performed to assess the association between categorical variables and knowledge score at the 5 percent significance level (p< 0.05). The knowledge level was divided into two groups after summation of total score: high knowledge (if total score is equal to or more than the mean total score), and poor (if total score is less than mean total score).