TABLE 4.

Risk of bias summary: author's judgement for each risk of bias domain and included study

First author [ref.]	Sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Abidi [11]	+	−	−	?	+	+	+
Castro [33]	+	?	+	?	+	+	+
Emelyanov [12]	+	?	+	?	+	+	+
Fogarty [24]	+	?	+	?	+	+	+
Govindan [13]	?	?	−	−	?	+	+
Gvozdjakova [14]	?	?	−	?	?	−	+
Hasselmark [15]	+	?	+	?	+	−	+
Hill [25]	+	?	+	?	−	+	+
Honma [16]	?	?	+	?	−	+	+
Kaslow [17]	?	?	+	?	+	+	+
Kelly-Pieper [29]	?	?	+	?	−	−	−
Khayyal [18]	?	?	?	?	+	+	+
Martineau [31]	+	?	+	?	+	+	+
Moreira [27]	+	+	+	?	−	+	+
Nadi [26]	?	?	+	?	?	+	+
Nanzer [32]	+	+	+	+	+	+	+
Okamoto [28]	?	?	?	?	?	−	+
Pearson [19]	+	?	+	+	+	+	+
Thomas [20]	?	?	+	?	−	+	+
Thoren [21]	?	?	+	?	+	+	+
Urata [22]	?	?	+	?	−	+	+
Wen [30]	?	?	+	?	+	+	−
Zhang [23]	+	?	?	?	−	+	+

+: low risk; ?: unclear risk; −: high risk.