Methodological index for non-randomized studies score.
| Criteria | Lewandrowski et al, 202315 | Wollf et al, 202016 | Pettine et al, 201717 | Atluri et al, 202118 | Orozco et al, 201119 | Kumar et al, 201720 |
| A clearly stated aim | 2 | 1 | 2 | 2 | 2 | 2 |
| Inclusion of consecutive patients | 2 | 2 | 2 | 2 | 2 | 2 |
| Prospective collection of data | 0 | 0 | 2 | 2 | 2 | 2 |
| Endpoint appropriate to the aim of the study | 2 | 2 | 2 | 2 | 2 | 2 |
| Unbiased assessment of the study endpoint | 1 | 1 | 0 | 0 | 1 | 1 |
| Follow-up period appropriate to the aim of the study | 2 | 2 | 2 | 2 | 2 | 2 |
| Loss of follow-up < 5% | 0 | 1 | 2 | 1 | 2 | 2 |
| Prospective calculation of the study size | 2 | 2 | 2 | 2 | 1 | 2 |
| Additional criteria for comparative studies | ||||||
| An adequate control group | NA | NA | NA | 2 | NA | NA |
| Contemporary group | NA | NA | NA | 2 | NA | NA |
| Baseline equivalent of groups | NA | NA | NA | 2 | NA | NA |
| Adequate statistical analysis | NA | NA | NA | 2 | NA | NA |
| Total | 11 | 11 | 14 | 21 | 14 | 15 |
Abbreviation: NA, not applicable.
Note: Low risk of bias : 13–16 (noncomparative studies), 20–24 (comparative studies); moderate risk of bias: 9–12 (noncomparative studies), 15–19 (comparative studies); high risk of bias: 0–8 (noncomparative studies), 0–14 (comparative studies).