Table 1 Cochrane quality scale for randomized controlled studies
Study | Allocation generation | Allocation concealment | Blinding of participants | Blinding of assessors | Outcome complete | Outcome selective | Other biases |
|---|---|---|---|---|---|---|---|
1998 Edward T | High | High | Unclear | Unclear | High | Unclear | High |
2006 Al Hallstrom | Medium | Medium | Unclear | Unclear | Medium | Unclear | Unclear |
2011 David Smekal | Medium | Low | Unclear | Unclear | Medium | Unclear | Unclear |
2014 Lars Wik | Medium | Low | Unclear | Unclear | Medium | Unclear | Unclear |
2014 Sten Rubertsson | Medium | Low | Unclear | Unclear | Medium | Unclear | Unclear |
2015 Gavin D Perkins | Low | Low | Unclear | Unclear | Low | Unclear | Unclear |
2016 Venkataraman | Medium | Medium | Unclear | Unclear | Medium | Unclear | Unclear |
2016 Chengjin Gao | Low | High | Unclear | Unclear | Medium | Unclear | Unclear |
2017 Bjarne | Medium | High | Unclear | Unclear | Medium | Unclear | Unclear |