Table 2.

Mean and median days of bleeding only and bleeding and spotting for the first 84 days, last 28-day cycles and all 112 days of the study period

	Bleeding and spotting					Bleeding only
	Mean (SE)	Median (range)	Mean difference	95% CI of difference	p value	Mean (SE) Median (range)	Mean difference	95% CI of difference	p value
First 84 days
Doxycycline group, n=32	14.75 (2.30)	11.0 (0, 47)	−3.03	−9.55, 3.49	.36	5.00 (1.03) 3.0 (0, 20)	−2.16	−5.51, 1.20	.20
Placebo group, n=32	17.78 (2.31)	17.0 (0, 48)				7.15 (1.32) 4.0 (0, 28)
Last 28 days
Doxycycline group, n=32	4.10 (1.23)	0 (0, 28)	−3.81	−7.46, 0.16	.04	1.03 (0.34) 0.0 (0, 7)	−1.53	−3.52, 0.46	.13
Placebo group, n=32	7.91 (1.35)	6.0 (0, 28)				2.56 (0.94) 0.0 (0, 28)
112 days
Doxycycline group, n=32	18.84 (3.30)	12.0 (0, 63)	−6.84	−16.08, 2.39	.14	6.03 (1.21) 4.0 (0, 24)	−3.69	−8.50, 1.13	.13
Placebo group, n=32	25.69 (3.24)	21.0 (0, 70)				9.72 (2.08) 5.0 (0, 56)