Table 5.

Quality (Risk-of-bias) assessment of included RCT

First author and year published	Items on SIGN checklist
	1	2	3	4	5	6	7	8	9	10	Quality
Peolsson et al. [32]	Y	Y	CS	N	CS	CS	CS	CS	CS	CS	L
Ren et al. [33]	Y	Y	Y	N	Y	Y	Y	N	CS	NA	A

Y = Yes, N = No, CS = Cannot say, NA = Not applicable

Quality: H = High, A = Acceptable, L = Low

SIGN, Scottish Intercollegiate Guideline Network

Quality assessment items from checklist:

1. Study addresses an appropriate and focused question

2. Assignment of subjects to treatment groups is randomized

3. An appropriate concealment method is used

4. Subjects and investigators are blind to treatment allocation

5. Treatment and control groups are comparable at start of trial

6. Only difference between groups is treatment under investigation

7. Relevant outcomes are measured using standard, valid, and reliable methods

8. Percentage (%) of dropout

9. Subjects are analyzed in the groups which they were randomly allocated (intention-to-treat analysis)

10. If study utilizes > 1 site, results are comparable across all sites