Methodological quality of the included studies according to the Newcastle Ottawa Scale
| Selection | Comparability | Outcome | |
| (max. score 4) | (max. score 2) | (max. score 3) | |
| Bean17 | 4 | 2 | 3 |
| Bravi10 | 4 | 2 | 3 |
| de Abajo11 | 4 | 2 | 3 |
| Giorgi Rossi12 | 4 | 2 | 3 |
| Liu13 | 4 | 2 | 1 |
| Mancia14 | 4 | 2 | 3 |
| Mehta19 | 3 | 2 | 1 |
| Reynolds15 | 4 | 2 | 3 |
| Tedeschi16 | 4 | 2 | 3 |
| Zhang18 | 4 | 2 | 3 |