Table 2 Bias Assessment for Individual Studies
Study | Selection Bias | Performance Bias | Detection Bias | Attrition Bias | Reporting Bias | Conflict of Interest |
|---|---|---|---|---|---|---|
Hallal, et al. (2007) [9] | Low | Low | Low | Low | Low | Unclear |
Palmer et al. (2008) [12] | Low | Low | Low | High | Low | High |
Rattanaumpawan et al. (2010) [14] | Unclear | High | Unclear | Low | Low | Low |
Lu et al. (2011) [10] | Unclear | High | High | Low | Low | Low |
Niederman et al. (2012) [11] | Low | High | High | High | High | High |
Palmer et al. (2014) [13] | Low | Low | Low | Low | Low | Unclear |