Figure 2

Quality assessment for studies using quantitative and qualitative methods. Footnote: Quantitative criteria applied to 169 studies (153 purely quantitative, 16 using both quantitative and qualitative methods). Qualitative criteria applied to 57 studies (41 purely qualitative and 16 using both quantitative and qualitative methods). * Rating for study design (poor = retrospective, fair = cross-sectional, good = prospective). ** Rating for acceptable response rate (poor <60% or unknown, fair 60%-69%, good ≥70%).