Table 2 Risk of bias assessment for the included studies, N = 14
S.No | Author and year | Random sequence generation | Allocation concealment | Blinding of the participants | Blinding of outcome assessment | Incomplete outcome data | Selective reporting of outcome |
|---|---|---|---|---|---|---|---|
1. | Bhageerathy et al. 2016 [22] | Low risk | Low risk | High risk | High risk | Low risk | Unclear risk |
2. | Boers et al. 2010 [15] | Low risk | Low risk | High risk | Unclear risk | Low risk | Low risk |
3. | Broekhuijsen et al. 2015 [23] | Low risk | Low risk | High risk | Unclear risk | Low risk | Low risk |
4. | Chappell et al. 2019 [24] | Unclear risk | Unclear risk | High risk | High risk | Unclear risk | Unclear risk |
5. | Duvekot et al. 2015 [25] | Low risk | Low risk | High risk | High risk | Low risk | Unclear risk |
6. | GRIT study group 2013 [26] | Low risk | Unclear risk | High risk | Unclear risk | Unclear risk | Low risk |
7. | Hamed et al. 2014 [16] | Low risk | Unclear risk | High risk | High risk | Low risk | Unclear risk |
8. | Koopmans et al. 2009 [27] | Low risk | Low risk | High risk | Unclear risk | Low risk | Low risk |
9. | Owens et al. 2014 [28] | Low risk | Unclear risk | High risk | Unclear risk | Unclear risk | Low risk |
10. | Majeed et al. 2014 [29] | Unclear risk | Unclear risk | High risk | High risk | Unclear risk | High risk |
11. | Mesbah EMM 2003 [30] | Low risk | Low risk | Unclear risk | Unclear risk | High risk | Low risk |
12. | Odendaal HJ et al. 1990 [32] | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk |
13. | Sibai BM et al. 1994 [33] | Low risk | Low risk | Unclear risk | Unclear risk | Low risk | Low risk |
14. | Vigil De Gracia et al. 2013 [31] | Low risk | Low risk | Unclear risk | Unclear risk | Low risk | Low risk |