Table 4.

Systematic Review/Meta-Analysis Modified SIGN Checklist

	Item	Yes/noa
1	Research question was clearly defined and eligibility criteria listed.
2	A comprehensive literature search was conducted.
3	At least two people selected studies.
4	At least two people extracted data.
5	The status of publication was not used as an inclusion criterion.
6	The excluded studies were listed.
7	The relevant characteristics of included studies were provided.
8	The quality of included studies was assessed and reported.
9	At least two people assessed quality of the included studies.
10	Appropriate methods were used to combine individual study results.
11	Likelihood of publication bias was assessed appropriately.
12	Conflicts of interest were declared.
	Total scoreb

^aRating: “Yes” = 1; “No” or unable to tell from the article = 0.

^bScoring—sum of items as follows: 10–12 = high quality, low risk of bias; 6–9 = acceptable quality, moderate risk of bias; <6 = low quality, high risk of bias.