Quintile of percent density | P* | Quintile of absolute density | P* | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

1 | 2 | 3 | 4 | 5 | 1 | 2 | 3 | 4 | 5 | |||||||||||

Percent dense volume (%) | Dense volume (cm^{3}) | |||||||||||||||||||

No. of cases | 62 | 64 | 75 | 78 | 85 | 64 | 68 | 61 | 86 | 85 | ||||||||||

No. of controls | 142 | 140 | 129 | 126 | 119 | 140 | 136 | 143 | 118 | 119 | ||||||||||

OR unadjusted (95% CI) | Reference | 1.05 (0.7, 1.6) | 1.33 (0.9, 2.0) | 1.42 (0.9, 2.1) | 1.64 (1.1, 2.5) | 0.01 | Reference | 1.09 (0.7, 1.7) | 0.93 (0.6, 1.4) | 1.59 (1.1, 2.4) | 1.56 (1.0, 2.3) | 0.1 | ||||||||

OR adjusted for risk factors^{†} (95% CI) | Reference | 1.08 (0.7, 1.6) | 1.39 (0.9, 2.1) | 1.60 (1.0, 2.5) | 1.98 (1.3, 3.1) | 0.001 | Reference | 1.10 (0.7, 1.7) | 0.98 (0.6, 1.5) | 1.69 (1.1, 2.6) | 1.68 (1.1, 2.6) | 0.003 | ||||||||

Percent dense area (%) | Dense area (cm^{2}) | |||||||||||||||||||

No. of cases | 70 | 60 | 76 | 76 | 82 | 71 | 62 | 69 | 78 | 84 | ||||||||||

No. of controls | 134 | 144 | 128 | 128 | 122 | 133 | 142 | 135 | 126 | 120 | ||||||||||

OR unadjusted (95% CI) | Reference | 0.80 (0.5, 1.2) | 1.14 (0.8, 1.8) | 1.14 (0.8, 1.7) | 1.29 (0.9, 1.9) | 0.06 | Reference | 0.82 (0.5, 1.2) | 0.96 (0.6, 1.4) | 1.16 (0.8, 1.7) | 1.31 (0.9, 2.0) | 0.05 | ||||||||

OR adjusted for risk factors^{†} (95% CI) | Reference | 0.92 (0.6, 1.4) | 1.41 (0.9, 2.2) | 1.49 (0.9, 2.3) | 1.86 (1.1, 3.0) | 0.003 | Reference | 0.90 (0.6, 1.4) | 1.07 (0.7, 1.6) | 1.29 (0.8, 2.0) | 1.48 (1.0, 2.3) | 0.02 |

NOTE: Shown are mean (SD) and percentage for, respectively, continuous and categorical variables.

↵* Unconditional logistic regression analysis.

*P*value is from a test of linear trend with quintiles as an ordinary variable in the model.↵† Age at mammogram (y), age at first birth (y), weight (kg), height (cm), menopausal status (premenopausal, postmenopausal), and parity (parous, nonparous).