Table 4.

Randomized Controlled Trial (Modified SIGN Checklist)

	Item	Yes/noa
1	Addressed an appropriate and clearly focused question.
2	Group assignment randomized.
3	Sample size justified by a power calculation.
4	Investigators blinded to patients' group assignment.
5	Patients blinded to group assignment.
6	Groups were similar at the start of the trial.
7	Only difference between groups was treatment of interest.
8	Outcomes measured in a standard, valid, and reliable way.
9	Power calculation was used and required sample size attained.
10	Intention-to-treat analysis performed.
	Total scoreb

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

^b Items scored as follows: 9–10 = high quality, low risk of bias; 6–8 = acceptable quality, moderate risk of bias; <6 = low quality, high risk of bias.