Quality Assessment
The nine of the included studies[22-30] were assessed for methodological quality using The Joanna Briggs Institute (JBI)[21]. Of them, one study[22] was assessed using the JBI Critical Appraisal Checklist for Cohort Studies[21], and the checklist contained a total of 11 assessment criteria (Table 2). Five studies[23,25,26,28,30] were evaluated by the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies[21], and the checklist contained 8 assessment criteria (Table 3). Three studies[24,27,29] were evaluated through the JBI Critical Appraisal Checklist for Prevalence Studies[21], and the checklist contained 9 assessment criteria (Table 4). Every criterion was given a rating of ‘yes’, ‘no’, ‘unclear’, or ‘not applicable’, and the overall scores in each study were the percentage of the number of ‘yes’ in the number of assessment criteria in each checklist. The percentage of overall scores in each study ranged from 78%[24,29] to 100%[23,25,26,28]. The higher of the percentage was meant that the better the quality of each study. Finally, no studies were excluded based solely on the assessment of methodological quality.