Table 1.
Number of screening examinations and mean measures
| Total | Group 1 ≤ 7.7 kPa |
Group 2 7.7–9.3 kPa |
Group 3 9.3–10.8 kPa |
Group 4 10.8–13.0 kPa |
Group 5 > 13.0 kPa |
|
|---|---|---|---|---|---|---|
| Number of examinations | 132,776 | 26,490 | 26,617 | 26,539 | 26,549 | 26,581 |
| Mean breast volume (cm3) | 974 | 1511 | 1135 | 928 | 755 | 540 |
| Mean percent dense volume (%) | 7.8 | 5.7 | 6.6 | 7.5 | 8.4 | 10.7 |
| Mean force (N) | 125.9 | 112.6 | 121.5 | 125.9 | 130.7 | 138.9 |
| Mean pressure (kPa) | 10.5 | 6.6 | 8.5 | 10.0 | 11.8 | 15.6 |
Thresholds to form the groups were applied at 7.7 kPa, 9.3 kPa, 10.8 kPa, and 13 kPa
An examination with a pressure measurement equal to the threshold was assigned to the lower group