| Study* | Newcastle–Ottawa Scale quality assessment score | ||
|---|---|---|---|
| Selection (max 4 stars) | Comparability (max 2 stars) | Outcome (max 3 stars) | |
| Postier et al. (18) | ★ ★ | ★ | ★ ★ ★ |
| Fraser et al. (11) | ★ ★ ★ | ★ | ★ ★ |
| Knapp et al. (15) | ★ ★ ★ | ★ | ★ ★ |
| Keele et al. (12) | ★ ★ ★ | ★ | ★ |
| Arland et al. (10) | ★ ★ ★ | ★ ★ | |
| Dussel et al. (14) | ★ ★ ★ | ★ | |
| Ward-Smith et al. (17) | ★ | ★ ★ | |
| Gans et al. (5) | ★ | ★ | ★ |
| Pascuet et al. (13) | ★ ★ | ★ | |
*The case series of 3 patients16 and the conference abstract19 were not included in the quality assessment.