Table II.

Effect sizes that studies have 80 and 90% power to detect, and effect sizes that were actually estimated by the studies, including the precision of the estimates as measured by width of 95% CI.

	What LBR improvements are studies powered to detect?		What LBR improvements are actually estimated in the studies?
	80% Power to detect	90% Power to detect	Estimated LBR improvement	Width of 95% CI
Largest RCT in comparison N = 199	19 (13 to 29)pp	22 (15–33)pp	0 (−4 to 6)pp	25 (16–39)pp
Meta-analysis for comparison N = 199	16 (9 to 27)pp	19 (11–31)pp	0 (−3 to 7)pp	21 (12–34)pp

Data are median (IQR).