Deep brain stimulation for obsessive-compulsive disorder: A systematic review of worldwide experience after 20 years

Table 1 Risk of bias for randomized controlled trials

Ref.	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Abelson et al[67], 2005			-	-	+
Barcia et al[32], 2019		+	-	-	-
Goodman et al[16], 2010			-	-	+
Huff et al[31], 2010					+
Luyten et al[20], 2016	+		-	-
Tyagi et al[17], 2019		+			+	+
Welter et al[39], 2020		+	-	-	-

+: High risk of bias; -: Low risk of bias. If there is no sign, the risk of bias is uncertain.