Table 5.

MPD at Baseline, Year 1, and Year 2, by Treatment Assignment and Percent Density at Baseline

Group	CEE MPD				Placebo MPD
	No.	Median	Mean	95% CI	No.	Median	Mean	95% CI
MPD first tertile < 1.5%
Baseline	66	0.5	0.6	0.5 to 0.7	77	0.5	0.6	0.5 to 0.7
Year 1	66	0.7	2.5	1.3 to 3.8	77	0.7	1.0	0.8 to 1.3
Year 2	60	0.9	2.5	1.4 to 3.5	71	0.7	1.1	0.9 to 1.4
Year 1−baseline	66	0.2	2.0	0.7 to 3.2	77	0.2	0.5	0.3 to 0.6
Year 2−baseline	60	0.5	1.9	0.9 to 2.9	71	0.3	0.6	0.3 to 0.9
MPD second tertile 1.5%-7.35%
Baseline	80	3.5	3.8	3.4 to 4.2	68	3.2	3.7	3.3 to 4.1
Year 1	80	3.3	5.9	4.5 to 7.2	68	3.0	3.8	2.7 to 4.8
Year 2	72	4.1	6.8	5.1 to 8.4	64	2.1	3.3	2.5 to 4.0
Year 1−baseline	80	−0.0	2.0	0.8 to 3.3	68	−0.8	0.1	−1.0 to 1.1
Year 2−baseline	72	0.5	2.9	1.4 to 4.5	64	−1.0	−0.5	−1.1 to 0.2
MPD third tertile ≥ 7.35%
Baseline	63	14.5	17.1	14.9 to 19.4	81	13.9	17.7	15.2 to 20.2
Year 1	63	16.8	17.9	15.7 to 20.1	81	11.2	14.4	12.1 to 16.6
Year 2	61	16.7	17.3	15.0 to 19.7	78	11.5	14.2	11.8 to 16.6
Year 1−baseline	63	0.2	0.8	−1.0 to 2.6	81	−3.4	−3.4	−4.8 to −2.0
Year 2−baseline	61	−1.0	0.0	−2.3 to 2.4	78	−3.6	−3.3	−4.8 to −1.9

NOTE. P = .38 for the interactiovisuln between CEE and baseline percent density is based on an 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.