Study design characteristics of the included data sets
| Questions studies | Scores | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Question(1) | Question(2) | Question(3) | Question(4) | Question(5) | Question(6) | Question(7) | Question(8) | Question(9) | Question(10) | Question(11) | |
| Liu et al.18 | Y | ? | Y | Y | N | N | Y | ? | Y | Y | Y |
| Kumar et al.19 | N | Y | N | Y | N | N | Y | Y | Y | Y | Y |
| Santiago et al.20 | N | ? | ? | Y | N | N | Y | Y | Y | Y | Y |
| Yan et al.21 | N | ? | N | Y | N | N | Y | Y | Y | Y | Y |
| Hiwatashi et al.22 | N | N | N | ? | N | N | N | ? | Y | Y | N |
| Schofer et al.23 | N | ? | N | Y | N | N | Y | Y | Y | Y | Y |
| Lovi et al.24 | N | ? | N | N | N | N | ? | Y | Y | Y | Y |
| Zhou et al.25 | N | N | N | ? | N | N | N | ? | ? | ? | Y |
| Frankel et al.26 | N | N | N | ? | N | N | ? | ? | N | ? | ? |
| De Negri et al.27 | N | N | N | ? | N | N | N | ? | ? | Y | Y |
| Grohs et al.28 | N | ? | Y | Y | N | N | N | Y | Y | Y | Y |
| Pflugmacher et al.29 | N | ? | N | Y | N | N | Y | Y | Y | Y | Y |
| Movrin et al.30 | N | ? | N | Y | N | N | Y | Y | Y | Y | Y |
| Röllinghoff et al.31 | N | ? | N | Y | N | N | Y | Y | Y | Y | Y |
| Pilát et al.32 | N | N | N | ? | N | N | N | ? | Y | Y | Y |
| N (total) | 14 | 5 | 12 | 2 | 15 | 15 | 5 | 0 | 1 | 0 | 1 |
| ? (total) | 0 | 9 | 1 | 5 | 0 | 0 | 2 | 6 | 2 | 2 | 1 |
| Y (total) | 1 | 1 | 2 | 9 | 0 | 0 | 8 | 9 | 9 | 13 | 13 |
Questions 1–11 were the 11 questions in the Methodological quality assessment scheme.21
Data were the responses to these questions for each article and the number of response “N,” “?,” or “Y” for each question.