Table 2.

Multiple linear regression of the association between treatment and each of the mammographic measures adjusted for different sets of covariates

CovariatesRegression coefficient (95% CI)P
Dense area*
    None−0.45 (−0.87 to −0.04)0.032
    Age−0.30 (−0.72 to 0.12)0.16
    Age, BMI−0.45 (−0.86 to −0.04)0.032
    Age, BMI, benign breast disease, and endometriosis−0.54 (−0.95 to −0.12)0.009
Percent density*
    None−0.17 (−0.62 to 0.28)0.47
    Age0.06 (−0.40 to 0.51)0.81
    Age, BMI−0.25 (−0.64 to 0.13)0.20
    Age, BMI, live births−0.28 (−0.67 to 0.11)0.16
    Age, BMI, live births, benign breast disease and endometriosis−0.32 (−0.70 to 0.07)0.11
Total breast area
    None−0.09 (−0.19 to 0.01)0.070
    Age−0.12 (−0.22 to −0.01)0.028
    Age, BMI−0.03 (−0.11 to 0.05)0.41
Nondense area
    None−0.08 (−0.23 to 0.08)0.32
    Age−0.14 (−0.30 to 0.01)0.072
    Age, BMI0.01 (−0.11 to 0.13)0.90
    Age, BMI, live births0.02 (−0.10 to 0.14)0.78

NOTE: Age (years), BMI (kg/m2), HRT (current), and menopause [postmenopausal if the time since last period was ≥52 weeks and (a) had not started HRT before periods ended or (b) started HRT before periods ended and ages ≥55 years].

  • *Square root transformed.

  • Log transformed.