Table 2.

Methodological quality of randomized controlled trials included in systematic review

	Yr	Randomisation method	Blind	Explanation for withdrawals	Allocation concealment	Jadad score
Cai et al[10]	2003	Random	Unclear	Yes	Unclear	3
Liu et al[11]	2003	Random	Unclear	Yes	Unclear	3
Gui et al[12]	2006	Unclear	Unclear	Yes	Unclear	2
Yang et al[13]	2002	Unclear	Unclear	Yes	Unclear	2
Jin et al[14]	2004	Unclear	Unclear	Yes	Unclear	2
Qian et al[15]	2006	Unclear	Unclear	Yes	Unclear	2
Yin et al[16]	2003	Unclear	Unclear	Yes	Unclear	2
Yang et al[17]	2006	Unclear	Unclear	Yes	Unclear	2
Jia et al[18]	2001	Random	Unclear	Yes	Unclear	3
Ge et al[19]	1997	Unclear	Unclear	Yes	Unclear	2
Jiang et al[20]	2007	Unclear	Unclear	Yes	Unclear	2
Guo et al[21]	2005	Unclear	Unclear	Yes	Unclear	2