Table 11.

Cochrane Collaboration’s tool for assessing risk of bias RoB 2.0 for RCT studies

Bias domain	Source of bias	Support for judgment	Review authors’ judgment (low, unclear or high risk of bias)
			R1: Ulusoy et al (2019)	R2: Kandemir Demirci et al (2019)
Selection bias	Random sequence generation	The allocation sequence was random. No baseline difference between the intervention groups could be detected	Low	Low
	Allocation concealment		Low	Low
Performance bias	Blinding of participants and personnel	R1: Blinding was not possible for obvious reasons R2: blinded participants but not personnel	High	Unclear
Detection bias	Blinding of outcome assessment	R1: Outcome assessors aware of the intervention received by study participants. Unclear if outcome assessment was influenced by knowledge of intervention received R2: radiological assessment by two independent blinded investigators	Unclear	Low
Attrition bias	Incomplete outcome data	R1 and R2: Data available for all, or nearly all, participants randomised	Low	Low
Reporting bias	Selective reporting	R1 and R2: no information if results were analysed in accordance with a prespecified analysis plan that was finalised before unblinded outcome data were available for analysis	Unclear	Unclear
Overall bias			Some concerns	Some concerns