Table 2.
Age, BMI and breast density characteristics of the Caucasian and African-American study groups
| Caucasian | African-American | p-value | |
|---|---|---|---|
| Number of women | 389 | 250 | |
| Age (Mean ± SD) | 53.1 y ± 7.1 | 51.8 y ± 7.6 | 0.03* |
| Gail lifetime risk (Mean ± SD) | 12.1% ± 4.8 | 8.6% ± 2.8 | <0.001* |
| Body mass index (BMI) | <0.001* | ||
| <25 kg/m2 | 197 (50.6%) | 36 (14.4%) | |
| 25-30 kg/m2 | 89 (22.9%) | 65 (26%) | |
| >30 kg/m2 | 68 (17.5%) | 118 (47.2%) | |
| Missing | 35 (9%) | 31 (12.4%) | |
| Absolute dense area (Mean ± SD) | 30.0 cm2 ± 16.6 | 29.8 cm2 ± 16.1 | 0.90 |
| Area percent density (Mean ± SD) | 20.1% ± 12.5 | 14.7% ± 9.7 | <0.001* |
| Absolute dense volume (Mean ± SD) | 137.7 cm3 ± 80.2 | 215.2 cm3 ± 138.0 | <0.001* |
| Volume percent density (Mean ± SD) | 25.1% ± 10.4 | 22.7% ± 9.6 | 0.003* |
Pearson χ2 test is used to test differences in BMI between the two groups; two-sample t-test with unequal variance is used to test for difference in age, Gail Lifetime Risk and breast density between the groups. * denotes statistical significance at the α = 0.05 level.