Table 2.
Downs and Black scale scores for the included studies by observer 1 and observer 2. The total scores and inter-observer agreement are also depicted in the table
| Study | Reporting | External validity | Internal validity- bias | Internal validity-confounding | Power | Total scores |
|---|---|---|---|---|---|---|
| Methodological assessment by author 1 | ||||||
| Aygun et al. 2019 [12] | 8 | 1 | 5 | 3 | 2 | 19 |
| Oztan et al. 2019 [2] | 7 | 2 | 5 | 3 | 5 | 22 |
| Duman et al. 2020 [1] | 7 | 1 | 5 | 3 | 0 | 16 |
| Gul et al. 2020 [13] | 7 | 1 | 5 | 3 | 5 | 21 |
| Ates et al. 2020 [14] | 8 | 1 | 5 | 3 | 3 | 20 |
| Methodological assessment by author 2 | ||||||
| Aygun et al. 2019 [12] | 8 | 1 | 5 | 3 | 2 | 19 |
| Oztan et al. 2019 [2] | 8 | 1 | 5 | 3 | 5 | 22 |
| Duman et al. 2020 [1] | 8 | 1 | 5 | 3 | 0 | 17 |
| Gul et al. 2020 [13] | 8 | 1 | 5 | 3 | 5 | 22 |
| Ates et al. 2020 [14] | 8 | 1 | 5 | 3 | 3 | 20 |