Table 3.

Unadjusted and Adjusted Longitudinal Analyses for Change in Percent Mammographic Density^a by Physical Activity Indices, Study of Women's Health Across the Nation, 1996–2004

Physical Activity Indexb	Model 1c		Model 2d		Model 3e
	β	95% Confidence Interval	β	95% Confidence Interval	β	95% Confidence Interval
Total activity	0.037	−0.027, 0.102	0.066	0.003, 0.130	0.087	0.024, 0.150
Sports/exercise	0.022	−0.083, 0.128	0.064	−0.040, 0.168	0.115	0.011, 0.219
Daily routine	0.045	−0.100, 0.190	0.128	−0.016, 0.272	0.149	0.009, 0.289
Household/caregiving	0.104	−0.036, 0.245	0.099	−0.038, 0.237	0.085	−0.051, 0.221

^aValues are maximum likelihood estimates of coefficients for modification to annual change in percent density and 95% confidence intervals from mixed-effects regression models.

^bOne unit change in index measured on a 1–15 scale for total activity and a 1–5 scale for individual domains.

^cModel 1 represents univariate models for each activity index.

^dModel 2 represents individual models for each activity index adjusted for body mass index.

^eModel 3 represents single models for each activity index adjusted for age, body mass index, menopausal status, race/ethnicity, study site, parity, past use of hormones (contraceptive and postmenopausal hormones), smoking, change in body mass index, and change in menopausal status.