TABLE 3.
Rate ratio of breast cancer incidence by BI‐RADS density code at first screen in recruitment period, Capital Region, Denmark, 2012 to 2020
| BI‐RADS | Rate ratio adjusted by running age, 95% confidence interval (in parentheses) | |||||
|---|---|---|---|---|---|---|
| Person‐years a | Breast cancer cases a | Follow‐up time | ||||
| Total | Total | Total BC/PY | 0‐<2 y | 2‐<5 y | 5+ y | |
| Code 1 | 351 823 | 888 |
1 (baseline) 888/351 823 |
1 (baseline) 335/3549 |
1 (baseline) 428/48 453 |
1 (baseline) 125/299 821 |
| Code 2 | 407 704 | 1684 |
1.69 (1.56‐1.84) 1684/407 704 |
1.83 (1.60‐2.09) 676/6131 |
1.53 (1.36‐1.72) b 761/65 809 |
1.69 (1.36‐2.09) 247/335 764 |
| Code 3 | 256 681 | 1265 |
2.06 (1.89‐2.25) 1265/256 681 |
2.02 (1.75‐2.32) 468/4510 |
2.04 (1.80‐2.32) 578/47 309 |
2.36 (1.89‐2.95) 219/204 863 |
| Code 4 | 47 954 | 256 |
2.37 (2.05‐2.74) 256/47 954 |
2.60 (2.07‐3.26) 107/1037 |
1.84 (1.50‐2.26) b 113/11 649 |
2.61 (1.79‐3.82) 36/35 268 |
Note: Total and by length of follow‐up. Adjusted by running age in 5‐years age groups.
Abbreviations: BC, breast cancer/ductal carcinoma in situ; PY, person‐years.
3131 person‐years and 17 breast cancer cases had missing BI‐RADS density code.
Crude rate ratio, as the model did not converge due to collinearity, but this means also that age‐adjustment would not change the estimate.