Table 4.

MPD at Baseline, Year 1, and Year 2, by Treatment Assignment and Gail Risk

Group	CEE MPD				Placebo MPD
	No.	Median	Mean	95% CI	No.	Median	Mean	95% CI
Low (< 1.7%)
Baseline	166	3.2	6.9	5.5 to 8.3	189	2.9	7.4	5.9 to 8.9
Year 1	166	3.8	8.2	6.7 to 9.7	189	2.9	6.4	5.1 to 7.7
Year 2	151	4.7	8.6	7.1 to 10.0	177	2.7	6.5	5.2 to 7.9
Year 1−baseline	166	0.1	1.3	0.4 to 2.1	189	−0.2	−1.0	−1.7 to −0.3
Year 2−baseline	151	0.3	1.2	0.1 to 2.3	177	−0.2	−1.1	−1.8 to −0.4
High
Baseline	43	3.8	6.3	4.4 to 8.2	37	5.5	9.1	5.8 to 12.3
Year 1	43	7.7	9.3	6.9 to 11.8	37	3.9	7.9	5.2 to 10.5
Year 2	42	6.7	9.6	6.7 to 12.4	36	4.8	6.8	4.4 to 9.3
Year 1−baseline	43	1.3	3.0	1.0 to 5.1	37	−0.3	−1.2	−2.8 to 0.4
Year 2−baseline	42	0.9	3.4	1.0 to 5.8	36	−0.5	−1.5	−2.7 to −0.3

NOTE. P = .02 for interaction between estrogen and menopausal hormone therapy is based on a two-sided F test from a repeated measures model with log (percent density + 0.001) as the response.

Abbreviations: MPD, mammographic percent density; CEE, conjugated equine estrogen.