Table 9. Cochrane tool for assessing risk of bias in RCTs.

RCTs, randomized controlled trials

Quality assessment of published studies included in the meta-analysis.

Study, year	Sequence generation	Allocation concealment	Blinding of participants	Blinding of outcome assessment	Incomplete outcome data	Selective outcome reporting	Other sources of bias
Pans, 1998 [9]	Unclear	Unclear	Unclear	Low	Low	Low	Low
Peña, 2003 [11]	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Strzelczyk, 2006 [12]	Low	High	High	Low	Low	Low	Low
El- Khadrawy, 2009 [1]	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Bevis, 2010 [13]	Low	Low	High	High	Low	Low	Low
Abo-Ryia, 2013 [16]	Unclear	Unclear	Low	Low	Low	Low	low
Armañanzas, 2014 [17]	Low	Low	Low	Low	Low	Low	Low
Sarr, 2014 [18]	Low	Low	Unclear	Unclear	Low	Low	low
Bali, 2015 [19]	Low	Unclear	Unclear	Unclear	Low	Low	Low
Muysoms, 2016 [20]	Low	Low	Low	High	Low	Low	Low
Jairam, 2017 [5]	Low	Low	Low	Low	Low	Low	Low
Kohler, 2018 [23]	Low	Low	Low	Low	Low	Low	Low
Glauser, 2019 [2]	Low	Low	Low	Low	Low	Low	Low
Caro‑Tarrago, 2019 [3]	Low	Low	Low	Low	Low	Low	Low