Table 3.
Summary of study quality assessment ratings for included studies.
| Study | Selection Bias | Study Design | Cofounders | Blinding | Data Collection Method | Withdrawals and Dropouts | Global Rating |
|---|---|---|---|---|---|---|---|
| Ajmani et al. (2016) India [24] |
3 | 3 | 3 | 3 | 1 | 3 | Weak |
| Ates et al. (2016) Turkey [37] |
1 | 3 | 3 | 3 | 1 | 1 | Weak |
| Aydogmus et al. (2015) Turkey [38] |
2 | 3 | 3 | 3 | 1 | 1 | Weak |
| Chen et al. (2015) China [35] |
1 | 3 | 1 | 3 | 1 | 1 | Weak |
| Farrant et al. (2009) India [34] |
2 | 3 | 3 | 3 | 1 | 2 | Weak |
| Gbadegesin et al. (2016) Nigeria [27] |
3 | 3 | 3 | 3 | 1 | 3 | Weak |
| Gur et al. (2014) Turkey [41] |
3 | 3 | 3 | 2 | 1 | 1 | Weak |
| Hossain et al. (2010) Pakistan [39] |
3 | 3 | 3 | 3 | 1 | 3 | Weak |
| Maghbooli et al. (2008) Iran [40] |
2 | 3 | 3 | 3 | 1 | 3 | Weak |
| Pirdehghan et al. (2016) Iran [25] |
3 | 3 | 3 | 2 | 1 | 3 | Weak |
| Song et al. (2012) China [26] |
3 | 3 | 3 | 3 | 1 | 3 | Weak |
| Toko et al. (2016) Kenya [6] |
3 | 3 | 1 | 3 | 1 | 3 | Weak |
| Xin et al. (2017) China [36] |
2 | 3 | 1 | 3 | 1 | 1 | Weak |
1: Strong; 2: Moderate; 3: Weak.