Table 6.
Outcomes for the exposed group by cancer type, calendar year of first CT scan, and no of years since first CT exposure, based on a one year lag period
| No of years since first exposure | Calendar year of first CT scan | |||
|---|---|---|---|---|
| 1985-89 | 1990-94 | 1995-99 | 2000-05 | |
| Brain cancer | ||||
| 1-4 | 38, 5.09 (3.60 to 6.99) | 25, 2.51 (1.63 to 3.71) | 25, 2.06 (1.34 to 3.05) | 33, 2.38 (1.64 to 3.35) |
| 5-9 | 38, 3.81 (2.70 to 5.23) | 22, 1.64 (1.03 to 2.48) | 20, 1.31 (0.80 to 2.02) | 3, 1.12 (0.23 to 3.27) |
| 10-14 | 18, 1.48 (0.88 to 2.34) | 23, 1.48 (0.94 to 2.21) | 5, 1.66 (0.54 to 3.88) | — |
| ≥15 | 26, 1.55 (1.02 to 2.28) | 7, 2.46 (0.99 to 5.07) | — | — |
| All years since first exposure | 120, 2.61 (2.17 to 3.13) | 77, 1.84 (1.47 to 2.32) | 50, 1.65 (1.24 to 2.19) | 36, 2.16 (1.53 to 3.04) |
| P<0.001 for trend in IRR with calendar year of first CT scan, after accounting for years since first exposure | ||||
| Other solid cancers | ||||
| 1-4 | 91, 1.23 (1.00 to 1.51) | 140, 1.20 (1.01 to 1.42) | 208, 1.29 (1.13 to 1.48) | 225, 1.19 (1.04 to 1.36) |
| 5-9 | 171, 1.10 (0.95 to 1.28) | 301, 1.32 (1.18 to 1.48) | 325, 1.14 (1.02 to 1.28) | 80, 1.38 (1.10 to 1.72) |
| 10-14 | 279, 1.12 (1.00 to 1.26) | 363, 1.11 (1.00 to 1.23) | 84, 1.19 (0.96 to 1.48) | — |
| ≥15 | 506, 1.22 (1.12 to 1.34) | 94, 1.20 (0.98 to 1.47) | — | — |
| All years since first exposure | 1047, 1.17 (1.10 to 1.25) | 898, 1.20 (1.12 to 1.28) | 617, 1.20 (1.10 to 1.30) | 305, 1.24 (1.10 to 1.39) |
| P=0.68 for trend in IRR with calendar year of first CT scan, after accounting for years since first exposure | ||||
| All cancers | ||||
| 1-4 | 129, 1.58 (1.33 to 1.88) | 165, 1.30 (1.12 to 1.52) | 233, 1.35 (1.18 to 1.53) | 258, 1.27 (1.13 to 1.44) |
| 5-9 | 209, 1.26 (1.10 to 1.45) | 323, 1.34 (1.20 to 1.49) | 345, 1.15 (1.04 to 1.28) | 83, 1.36 (1.10 to 1.69) |
| 10-14 | 297, 1.14 (1.01 to 1.27) | 386, 1.12 (1.02 to 1.24) | 89, 1.20 (0.98 to 1.48) | — |
| ≥15 | 532, 1.24 (1.14 to 1.35) | 101, 1.24 (1.02 to 1.51) | — | — |
| All years since first exposure | 1167, 1.24 (1.17 to 1.32) | 975, 1.23 (1.15 to 1.31) | 667, 1.22 (1.13 to 1.32) | 341, 1.29 (1.16 to 1.44) |
| P=0.18 for trend in IRR with calendar year of first CT scan, after accounting for years since first exposure | ||||
Figures shown are observed number of cancers in exposed group, incidence rate ratio (IRR), exposed v unexposed, (95% confidence interval) calculated after stratification for age, sex, and year of birth.