Table A1.
Quality assessment of studies.
| Study | SD | RSG | AC | Blinding of Research | Blinding of PP | Blinding of OA | LE | Do They Describe Confounders in an Adjusted Analysis? | Do You Assess the Balance between the Groups at the Start of the Study? |
|---|---|---|---|---|---|---|---|---|---|
| Rifai et al. [25] | RCT | Low risk | Unclear risk | High risk | High risk | High risk | Unclear risk | NA | NA |
| Silver * [17] | RCT | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | NA | NA |
| Vittos et al. * [21] | Cohort | NA | NA | NA | NA | NA | NA | Unclear risk | Low risk |
| Hummel et al., (2012) [23] | Cohort | NA | NA | NA | NA | NA | NA | Unclear risk | Low risk |
| Hummel et al., (2013) [24] | Cohort | NA | NA | NA | NA | NA | NA | Unclear risk | Low risk |
| Hummel et al., (2014) * [20] | Cohort | NA | NA | NA | NA | NA | NA | Low risk | Unclear risk |
| Chrysohoou et al., (2009a) * [18] | Cross-sectional study | NA | NA | NA | NA | NA | NA | Low risk | Unclear risk |
| Chrysohoou et al. (2009b) * [19] | Cross-sectional study | NA | NA | NA | NA | NA | NA | Low risk | Unclear risk |
| Chrysohoou et al., (2012) [26] | Cross-sectional study | NA | NA | NA | NA | NA | NA | Low risk | Low risk |
| Levitan et al. [22] | Cohort | NA | NA | NA | NA | NA | NA | Low risk | Low risk |
| Gonzales et al. * [16] | RCT | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | NA | NA |
| Evangelista et al. [27] | RCT | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | NA | NA |
* Abstract; NA: not applicable; SD: study design; RSG: random sequence generation; AC: allocation concealment; PP: participants and personnel; OA: outcome assessment; LE: losses and exclusions.