Table 6. ORs and 95% CIs for stroke in association with daily fraction radiation doses.
| Case | Control | OR | Age adjusted | |
|---|---|---|---|---|
| Daily fraction radiation dose IMC | ||||
| No RT | 184 | 189 | ref | |
| ⩽2.5 Gy | 20 | 34 | 0.56 | (0.24, 1.31) |
| 2.6–3.9 Gy | 64 | 49 | 2.61 | (1.48, 4.60) |
| ⩾4 Gy | 11 | 10 | 3.05 | (0.97, 9.58) |
| Unclear | 3 | 0 | — | — |
| Daily fraction radiation dose SCL | ||||
| No RT | 183 | 190 | ref | |
| ⩽2.5 Gy | 19 | 33 | 0.54 | (0.23, 1.29) |
| 2.6–3.9 Gy | 45 | 36 | 2.14 | (1.15, 3.99) |
| ⩾4 Gy | 32 | 23 | 4.06 | (1.85, 8.94) |
| Unclear | 3 | 0 | — | — |
CI=confidence interval; IMC=internal mammary chain; OR=odds ratio; RT=radiotherapy; SCL=supraclavicular.