Included studies

Publishing time

Document type

Evidence lifting factor

Grade

Fushan Qin [20]

2007

CR

Nothing

Low

Tao Zhang [21]

1993

CR

Added drug interference (−1)

Very low

Huaisheng Li [22]

1996

CR

Added drug interference (−1)

Very low

Chonglin Mou [23]

1997

CR

Added drug interference (−1)

Very low

Yan Shi [24]

2001

CR

Added drug interference (−1)

Very low

Xiaofen Wei [25]

2002

CR

Added drug interference (−1)

Very low

Weiping Shen [26]

2003

CR

Added drug interference (−1)

Very low

Yufang He [27]

2005

'RCT

Limitation of the study (−2)

Very low

Added drug interference (−1)

Yijuan Zhang [28]

2006

CR

Added drug interference (−1)

Very low

Jianchun Yu [29]

2008

CR

Added drug interference (−1)

Very low