Table 2. Quality of included RCTs.

	Randomization method	Blind method	Jadad score
Purrello, et al.(2007) [16]	Random sampling	None	6
Feng-Shang Zhu, et al.(2008) [17]	Not stated	None	4
Qing Xie, et al.(2008) [18]	Not stated	Double blind	4
Sofi, et al.(2010) [15]	Not stated	None	6
Byrne, et al.(2014) [19]	Not stated	None	5
Stephen, et al.(2015) [21]	Stratified block 1:1 randomization scheme	Double blind	6
Lu-Hua Yang, et al.(2015) [20]	Not stated	Double blind	4