Table 3.

Cochrane’s classification for risk of bias

Source	Random sequence generation	Allocation concealment	Blinding of participants	Blinding of outcome assessment	Incomplete outcome data	Selective outcome reporting	Other source of bias
Tollefson et al. [38], 1998	Low	Low	Low	Low	Low	Low	Low
Davis and Chen [36], 2001	Low	Low	Low	Low	Low	Low	Low
Conley and Mahmoud [42], 2001	Low	Low	Low	Low	Low	Low	Low
Jeste et al. [43], 2004	Low	Low	Low	Low	Low	Low	Low
Lindenmayer et al. [40], 2004	Low	Low	Low	Low	Low	Low	Low
Ascher-Svanum et al. [37], 2005	Low	Low	Low	Low	Low	Low	Low
Wang et al. [41], 2006	Low	Low	Low	Low	Unclear	Unclear	High