Table 2.
Risk of Bias and Methodological Quality Assessment of Observational Studies.
| Study | Representativeness | Comparability | Outcome assessment | % loss to follow-up |
|---|---|---|---|---|
| Weng34 | + | + | + | ? |
| Medcalf30 | + | + | + | + |
| Tsao35 | + | ? | − | ? |
| Elinder10 | + | + | + | ? |
| Gjertson12 | + | + | + | ? |
| Kim6 | − | + | + | ? |
| Axelrod20 | + | + | + | ? |
| Doxiadis31 | − | ? | − | ? |
| Briganti11 | + | + | + | + |
| Gjertson21 | − | + | + | ? |
| Gjertson22 | − | + | − | − |
| Pontin36 | − | ? | − | ? |
| Schurman23 | + | − | − | ? |
| Terasaki24 | ? | ? | − | ? |
| Morris32 | − | + | + | + |
| Gjertson25 | − | + | + | ? |
| Hunsicker26 | ? | − | − | + |
| Gjertson27 | − | + | + | ? |
| Evans28 | − | + | − | ? |
| Ogura7 | − | − | − | ? |
| Terasaki33 | − | − | + | ? |
| Sanfillipo29 | − | + | + | ? |
| Taylor19 | − | − | + | ? |
| Opelz9 | + | − | − | ? |
Note. “+” indicates low risk of bias; “–” indicates high risk of bias; “?” indicates unclear.