Table 1 Assessment quality of included studies
Study | Trial type | Randomization | allocation concealment | Blinding | Lost of follow up | ITT | Grade |
|---|---|---|---|---|---|---|---|
Kubo S (2002) [9] | RCT | Adequate | Unclear | Adequate | Yes | Yes | B |
Shiratori Y (2003) [10] | RCT | Adequate | Adequate | Adequate | Yes | Yes | A |
Lin SM (2004) [11] | RCT | Unclear | Unclear | Unclear | Yes | Yes | B |
Piao CY (2005) [12] | RCT | Adequate | Unclear | Adequate | Yes | Yes | B |
Mazzaferro V (2006) [13] | RCT | Adequate | Unclear | Unclear | Yes | Yes | B |
Sun HC (2006) [14] | RCT | Adequate | Adequate | Adequate | Yes | Yes | A |
Lo CM (2007) [15] | RCT | Adequate | Adequate | Unclear | Yes | Yes | B |
Li M (2009) [16] | RCT | Adequate | Unclear | Unclear | Yes | Yes | B |
Li N (2010) [17] | NRCT | Adequate | Adequate | Unclear | Yes | Yes | B |
Ishikawa (2012) [18] | NRCT | Adequate | Unclear | Unclear | Yes | Yes | B |