2.

纳入研究方法学质量评价

Quality assessment of methodology of included studies

Included studies	Sequence generation	Allocated concealment	Blinding	Withdraw	Fellow-up	Quality grading
Bian GM[11]	Unclear	Unclear	Unclear	No	Unclear	B
Chen XM[12]	Unclear	Unclear	Unclear	No	Unclear	C
Hou EC[13]	Envelope	Unclear	Unclear	No	Unclear	B
Li XD[14]	Unclear	Unclear	Unclear	No	Unclear	B
Lin Q[15]	Unclear	Unclear	Unclear	No	Unclear	C
Peng RT[16]	Unclear	Unclear	Unclear	No	Unclear	B
Su W[17]	Unclear	Unclear	Unclear	No	Unclear	B
Wang HM[18]	Unclear	Unclear	Unclear	No	Unclear	B
Yang G[19]	Unclear	Unclear	Unclear	No	Unclear	B
Zhou H[20]	Unclear	Unclear	Unclear	No	Unclear	C
Zhu QS[21]	Random digits table	Unclear	Unclear	No	Unclear	B