| Author |
Bias due to confounding |
Bias in the selection of participants in the study |
Bias in the classification of interventions |
Bias due to deviations from intended interventions |
Bias due to missing data |
Bias in the measurement of outcomes |
Bias in the selection of the reported result |
Overall bias |
| Villa et al., 2007 [12] |
2 |
2 |
3 |
3 |
2 |
2 |
2 |
16 |
| Pirelli et al., 2004 [13] |
2 |
2 |
1 |
2 |
1 |
2 |
2 |
12 |
| Villa et al., 2002 [14] |
2 |
3 |
2 |
2 |
1 |
2 |
2 |
14 |
| Guilleminault et al., 2011 [15] |
2 |
3 |
1 |
2 |
3 |
3 |
1 |
14 |
| Marino et al., 2012 [16] |
2 |
3 |
2 |
2 |
2 |
1 |
2 |
14 |
| Pirelli et al., 2012 [17] |
2 |
2 |
1 |
1 |
3 |
1 |
2 |
10 |
| Cozza et al., 2004 [18] |
2 |
2 |
3 |
2 |
1 |
2 |
2 |
14 |
| Caruso et al., 2023 [19] |
2 |
2 |
3 |
3 |
2 |
2 |
2 |
16 |
| Pirelli e al., 2015 [20] |
2 |
3 |
1 |
2 |
2 |
3 |
1 |
13 |
| Villa Met al., 2015 [21] |
2 |
3 |
1 |
1 |
2 |
1 |
1 |
11 |
| Pirelli et al., 2019 [22] |
2 |
3 |
1 |
2 |
3 |
3 |
1 |
14 |
| Pirelli et al., 2021 [23] |
2 |
2 |
1 |
1 |
3 |
1 |
2 |
10 |
| Kim et al., 2022 [24] |
2 |
2 |
3 |
2 |
1 |
2 |
2 |
14 |
| Li et al., 2022 [25] |
2 |
2 |
3 |
3 |
2 |
2 |
2 |
16 |
| Chuang et al., 2019 [26] |
2 |
3 |
1 |
2 |
2 |
3 |
1 |
13 |
| Ghodke et al., 2014 [27] |
2 |
3 |
1 |
1 |
2 |
1 |
1 |
11 |
| Machado-Júnior et al., 2016 [28] |
2 |
2 |
3 |
3 |
2 |
2 |
2 |
16 |
| Concepción Medina et al., 2022 [29] |
2 |
2 |
1 |
2 |
1 |
2 |
2 |
12 |
| Zhang et al., 2013 [30] |
2 |
3 |
2 |
2 |
1 |
2 |
2 |
14 |
| Zhao et al., 2018 [31] |
2 |
3 |
1 |
2 |
3 |
3 |
1 |
14 |
| Zreaqat et al., 2023 [32] |
2 |
3 |
2 |
2 |
2 |
1 |
2 |
14 |
