Table 5.
Association of continuous density with risk, by centre and number of views available
| Centre | Number of views | Number of subjects | Mean (SD) density, cancers | Mean (SD) density, noncancers | OR per 10% density (95% CI) | % attributable fraction to densities > 20% |
| Manchester | 1 | 3,416 | 39.8 (18.5) | 32.2 (17.5) | 1.22 (1.09 to 1.36) | 3 |
| 2 | 1,721 | 51.1 (19.7) | 37.4 (19.7) | 1.41 (1.19 to 1.66) | 35 | |
| Aberdeen | 1 | 3,674 | 32.2 (21.1) | 30.6 (21.8) | 1.03 (0.95 to 1.11) | 30 |
| 2 | 1,191 | 52.0 (24.0) | 36.8 (24.4) | 1.28 (1.11 to 1.46) | 50 | |
CI, confidence interval; OR, odds ratio; SD, standard deviation.