Table 3.
Subsequent use of mammography, ultrasound, biopsy/invasive procedures, or any follow-up in the years before and after introduction of digital mammography, overall and stratified by initial screening examination result.
| Year Before Digital N (%) | 1 Year After Digital N (%) | 2 Years After Digital N (%) | 3 Years After Digital N (%) | 4 Years After Digital N (%) | |
|---|---|---|---|---|---|
| All, N | 8450 | 6327 | 6652 | 5522 | 3260 |
| Mammography | 827 (9.8) | 830 (13.1) | 923 (13.9) | 597 (10.8) | 275 (8.4) |
| Ultrasound | 325 (3.8) | 324 (5.1) | 273 (4.1) | 217 (3.9) | 129 (4.0) |
| Biopsy | 131 (1.6) | 103 (1.6) | 84 (1.3) | 69 (1.2) | 39 (1.2) |
| Any follow-up | 947 (11.2) | 936 (14.8) | 1007 (15.1) | 688 (12.5) | 316 (9.7) |
| Negative*, N | 7765 | 5590 | 5787 | 4837 | 3025 |
| Mammography | 318 (4.1) | 249 (4.5) | 413 (7.1) | 208 (4.3) | 70 (2.3) |
| Ultrasound | 90 (1.2) | 68 (1.2) | 59 (1.0) | 56 (1.2) | 37 (1.2) |
| Biopsy | 51 (0.7) | 25 (0.4) | 28 (0.5) | 25 (0.5) | 18 (0.6) |
| Any follow-up | 384 (4.9) | 294 (5.3) | 453 (7.8) | 257 (5.3) | 101 (3.3) |
| False-positive or short interval follow-up*, N | 595 | 674 | 695 | 528 | 229 |
| Mammography | 500 (84.0) | 575 (85.3) | 499 (71.8) | 377 (71.4) | 205 (89.5) |
| Ultrasound | 231 (38.8) | 254 (37.7) | 211 (30.4) | 160 (30.3) | 92 (40.2) |
| Biopsy | 78 (13.1) | 76 (11.3) | 54 (7.8) | 43 (8.1) | 21 (9.2) |
| Any follow-up | 553 (92.9) | 635 (94.2) | 541 (77.8) | 417 (79) | 215 (93.9) |
*
Mammograms with missing results or recommendations (1.4%) were excluded from analysis.