Table 1

Risk of bias assessment for randomised (top; N=100) and non-randomised trials (bottom; N=14) with percentages of low-risk, unclear-risk and high-risk evaluations expressed relative to the number of treatment arms (upper value) and the total number of data points (lower value)

		Random sequence allocation	Allocation concealment	Blinding of participants	Blinding of outcome assessors	Incomplete outcome bias	Selective reporting	Other bias
Randomised controlled trials	Low risk
	Unclear
	High risk
Non-randomised controlled trials	Low risk
	Unclear
	High risk