Table 2.

Quality assessment of included studies.

Study	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	Score
Heng et al., 2016	√	√	√		√			√	√	6
Jiang et al., 2015	√	√	√		√		√	√	√	6
Zhou et al., 2015	√	√	√		√		√	√	√	7
Chen et al., 2005	√		√				√	√	√	5
Chen et al., 2002	√		√		√		√	√		5
Wei et al., 2015	√		√				√			3
Wang et al., 2015	√	√	√				√			4
Zhu et al., 2014	√	√	√		√			√		5
Wang et al., 2014	√	√	√					√		4
Yan et al., 2014	√	√	√				√			4
Liu et al., 2008	√	√	√		√			√		5
Yang et al., 2009	√		√		√		√	√		5
Ji, 2008	√	√	√		√			√		5
Wang et al., 2008	√	√	√					√		4
Yang et al., 2007	√	√	√		√		√	√		6
Zhou et al., 2003	√		√		√			√		4
Meng et al., 2001	√	√	√		√			√		5
Yang, 2014	√	√	√		√			√		5
Wang et al., 2009	√	√	√		√			√		5
Xu et al., 2009	√	√	√		√		√	√	√	7
Jie, 2010	√		√		√		√	√		5
Xu et al., 2008	√	√	√		√		√	√		6
Xu and Chen, 2007	√	√	√		√		√	√		6
Zhou et al., 2016	√	√	√		√		√	√		6
Sun et al., 2016	√		√		√		√	√		5

Note: (1) peer reviewed publication; (2) control of temperature; (3) random allocation to groups; (4) blinded assessment of behavioral outcome; (5) use of anesthetic without significant intrinsic neuroprotective activity; (6) calculation of the sample size necessary to achieve sufficient power; (7) appropriate animal model (aged, diabetic, or hypertensive); (8) compliance with animal welfare regulations; (9) statement of potential conflict of interests.