Acupuncture for Posttraumatic Stress Disorder: A Systematic Review of Randomized Controlled Trials and Prospective Clinical Trials

Table 2

Cochrane risk of bias of included randomized controlled trials.

First author [ref]; (Year)	Hollifield [18]; (2007)	Zhang [25] (2010)	Zhang [26](2010)	Zhang [27]; (2011)
(1) Random sequence generation; (selection bias)	L; (computerized randomization)	L; (computerized randomization)	U	U
(2) Allocation concealment; (selection bias)	L; (central allocation)	L; (sequentially numbered, opaque sealed envelopes)	U	U
(3) Blinding of participants; (performance bias)	H	H	H	H
(4) Blinding of outcome assessment; (detection bias)	L; (mentioned)	L; (mentioned)	U	U
(5) Incomplete outcome data; (attrition bias)	L; (mentioned)	U	U	U
(6) Selective reporting; (reporting bias)	U	U	U	U
(7) Other sources of bias; (other bias)	U	U	U	U

L: low risk of bias; H: high risk of bias; U: unclear.