Table 3.

The modified Jadad questionnaire for the included studies.

Study, year (Station)	Random sequence production			Allocation concealment				Blinding metod			Withdrawals and dropouts		Score
	Adequate 2’	Unclear 1’	Inadequate 0’	Adequate 2’	Unclear 1’	Inadequate 0’	Unused 0’	Adequate 2’	Unclear 1’	Inadequate 0’	Description 1’	Undescribed 0’
Wang et al., 2007		1			1			2				0	4
Jiang et al. (2006)		1			1			2				0	4
Karnad et al., 2014		2			2			2			1		7
Wu et al., 2013b		2			1			2				0	5
Sung et al., 2009		1			1				1			0	3
Wu et al., 2016		1			1			2				0	4
Dai et al. (2016)		2			1			2				0	5
Tang et al. (2013)		1			1			2				0	4
Chen et al., 2015		1			1			2				0	4
Fang et al. (2005)		1			1			2				0	4
Ni et al. (2008)		2			1			2				0	5
Shao et al., 2005	2			2				2				0	6
Fang and Zhao, 2017	2			2				2				0	6
Pavan Kumar et al., 2017		1			1				1			0	3
Choudhuri et al., 2015		1			1				1			0	3

1–3 score, low quality; 4–7 score, high quality.