Table 2.

Risk of bias assessment (Cochrane randomized controlled trials) for controlled trials.

	Random sequence generation	Allocation concealment	Binding‐participants and personnel	Binding‐outcome assessment	Incomplete outcome data	Selective outcome reporting
Bamber et al. 2013	+	+	?	?	+	+
Coleman et al. 2016	−	−	−	−	+	+
Hohnloser et al. 2015	+	−	−	−	+	+
Koretsune et al. 2017	+	−	−	−	+	+
Monz et al. 2013	+	+	+	+	+	+
Prins et al. 2015	+	+	+	−	−	−

+ = low risk of bias.

– = high risk of bias.

? = unclear risk of bias.