Table 1.

Report quality of included studies.

Section/topic	Item no.	Checklist item	Number of studies reported	Ratio (%)
Title	1	Title	172	100
Abstract	2	Structured summary	149	86.63
Introduction	3	Rationale	172	100
	4	Objectives	172	100
Methods	5	Protocol and registration	19	11.05
	6	Eligibility criteria	170	98.84
	7	Information sources	172	100
	8	Search	172	100
	9	Study selection	98	56.98
	10	Data collection process	164	95.35
	11	Data items	168	97.67
	12	Risk of bias in individual studies	135	78.49
	13	Summary measures	169	98.26
	14	Synthesis of results	172	100
	15	Risk of bias across studies	93	54.07
	16	Additional analyses	105	61.05
Results	17	Study selection	169	98.26
	18	Study characteristics	172	100
	19	Risk of bias within studies	140	81.4
	20	Results of individual studies	172	100
	21	Synthesis of results	172	100
	22	Risk of bias across studies	97	56.4
	23	Additional analysis	146	84.88
Discussion	24	Summary of evidence	172	100
	25	Limitations	144	83.72
	26	Conclusions	172	100
Funding	27	Funding	92	53.49