Type of study | Number of included studies |
Systematic reviews | 22 (11%) |
Randomised control trials | 5 (2.5%) |
Cross-sectional studies | 118 (59.5%) |
Cohort studies | 43 (22%) |
Qualitative studies | 5 (2.5%) |
Other | 5 (2.5%): 1 thesis, 1 non-randomised controlled trial, 2 non-systematic ‘review’ articles and 1 mixed case report and non-systematic review |