Table 3B.

Observed effect size (based on rank-transformed data) and Hodges-Lehmann 95% CI for the difference between population medians for nonparametric data

Outcome	CPAP median (min, max)	Bi-Flex median (min, max)	Mann-Whitney p value	Effect size*	Probabilistic index**	Observed median difference	Population median difference	95% CI of population difference
Number of nights used, Month 1	26 (13, 31)	27 (1, 31)	0.93	0.03	0.49	1.0	0.0	−5, 4
△AHI	−13.7 (−42.8, 6.4)	−8.8 (−62.1, 5.1)	0.82	0.07	0.48	4.9	0.5	−10.3, 8.1

AHI, apnea hypopnea index.

^*Based on rank-transformed data. The difference between the 2 groups' mean ranks divided by the average SD of their ranks.

^**Probabilistic Index = [2(U/mn) −1], where U/mnis the Mann-Whitney Ustatistic divided by the product of the 2 sample sizes.