Table 2 Quality assessment of the included studies
From: Cetuximab for esophageal cancer: an updated meta-analysis of randomized controlled trials
Bias | Selection bias | Performance bias | Attrition bias | Reporting bias (no selective reporting) | Detection bias | Study quality (score) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Study | Adequate random sequence generation | Similar baseline condition | Adequate allocation concealment | Adequate participant blinding | Adequate provider blinding | Similar or no co-interventions | Acceptable compliance | Acceptable drop-out rate | intention-to-treat analysis | Adequate outcome assessor blinding | Similar timing of outcome assessment | ||
Studies included non-metastatic esophageal cancer | |||||||||||||
 Rades et al. (2014) [23] | Unclear | Unclear | Unclear | Unclear | Unclear | Yes | Yes | Unclear | Yes | Yes | Unclear | Yes | Moderate (5) |
 Zhang et al. (2014) | Unclear | Unclear | Unclear | Unclear | Unclear | Yes | Unclear | Yes | Yes | Yes | Unclear | Yes | Moderate (5) |
 Crosby et al. (2017) [21] | Yes | Yes | Yes | No | Unclear | Yes | No | Yes | Yes | Yes | Unclear | Yes | high (8) |
 Ruhstaller et al. (2017) | Unclear | Yes | Unclear | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear | Yes | Moderate (7) |
 Suntharalingam et al. (2017) [28] | Unclear | Yes | Unclear | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear | Yes | Moderate (7) |
Studies included metastatic esophageal cancer | |||||||||||||
 Lorenzen et al. (2009) [14] | Unclear | Yes | Unclear | Unclear | Unclear | Yes | Yes | Yes | Yes | Yes | Unclear | Yes | Moderate (7) |
 Chen et al. (2014) [22] | Unclear | Yes | Unclear | Unclear | Unclear | Yes | Unclear | Unclear | Yes | Yes | Unclear | No | Low (4) |
 Feng et al. (2017) [25] | Yes | Yes | Unclear | Unclear | Unclear | Yes | Unclear | Yes | Yes | Yes | Unclear | Yes | Moderate (7) |
 Yang et al. (2017) [26] | Unclear | Yes | Unclear | Unclear | Unclear | Yes | Unclear | Yes | Yes | Yes | Unclear | Yes | Moderate (6) |
 Lu et al. (2017) [16] | Yes | Yes | Unclear | Unclear | Unclear | Yes | Unclear | Yes | Yes | Yes | Unclear | Yes | Moderate (7) |