Table 3.
Quality assessment of the included studies
| Studies | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Final rating |
|---|---|---|---|---|---|---|---|---|---|
| Silva et al. (2009) | W | S | S | M | M | S | S | S | Moderate |
| Oliveira and Silva (2016) | M | M | S | W | S | W | S | S | Moderate |
| Nagai et al. (2014) | W | M | S | W | M | W | S | M | Weak |
| Mani et al. (2017) | W | M | W | W | W | W | S | W | Weak |
| Lau et al. (2010) | W | M | S | W | S | W | S | S | Weak |
| Dunleavy et al. (2015) | W | M | S | W | S | W | S | M | Weak |
| Cheung et al. (2010) | S | S | M | M | M | W | S | M | Moderate |
| Nejati et al. (2015) | M | M | M | W | W | M | S | M | Moderate |
| Helgadottir et al. (2011) | W | S | S | M | W | S | S | M | Moderate |
| Ruivo et al. (2014) | M | M | M | M | M | M | S | M | Moderate |
| Kim and Kim (2016) | W | M | W | W | W | M | S | M | Weak |
| Lau et al. (2010) | W | M | W | M | S | W | S | M | Weak |
| Dolphens et al. (2012) | S | M | M | W | W | M | S | S | Moderate |
| Richards et al. (2016) | S | M | S | W | W | M | S | S | Moderate |
| Arun et al. (2017) | W | M | W | W | M | M | S | M | Weak |
1, selection bias; 2, study design; 3, controlling confounders; 4, blinding; 5, data collection methods; 6, sample size; 7, withdrawals; 8, analyses (S = strong, M = moderate, W = weak)