Cardiovascular disease mortality and cumulative extremely low-frequency magnetic field exposure
| Cumulative exposure (tertiles among ever low and high exposed) | ||||||
|---|---|---|---|---|---|---|
| 0 unit-years | 0.5–9 unit-years | 9.5–28 unit-years | 28.5–208 unit-years | Test for trend* | Test for trend amongst low or high exposed† | |
| Person-years in subcohort | 17726 | 6626 | 5864 | 5972 | ||
| Ischaemic heart diseases (IHD) | ||||||
| Cases | 1589 | 402 | 501 | 800 | ||
| HR‡ (95% CI) | 1 | 0.98 (0.82 to 1.17) | 0.98 (0.84 to 1.14) | 0.98 (0.85 to 1.14) | 0.21 | 0.18 |
| Acute myocardial infarction (AMI) | ||||||
| Cases | 1078 | 289 | 367 | 547 | ||
| HR‡ (95% CI) | 1 | 1.01 (0.84 to 1.22) | 1.05 (0.89 to 1.24) | 1.02 (0.87 to 1.19) | 0.18 | 0.17 |
| Subacute and chronic IHD | ||||||
| Cases | 511 | 113 | 135 | 256 | ||
| HR‡ (95% CI) | 0.92 (0.71 to 1.19) | 0.83 (0.66 to 1.04) | 0.93 (0.76 to 1.12) | 0.41 | 0.35 | |
| Other cardiac causes | ||||||
| Cases | 525 | 146 | 176 | 237 | ||
| HR‡ (95% CI) | 1 | 1.00 (0.79 to 1.26) | 1.03 (0.84 to 1.27) | 0.97 (0.80 to 1.19) | 0.86 | 0.84 |
| Arrhythmias | ||||||
| Cases | 67 | 24 | 26 | 30 | ||
| HR‡ (95% CI) | 1 | 1.14 (0.67 to 1.95) | 1.32 (0.83 to 2.09) | 0.99 (0.61 to 1.61) | 0.64 | 0.55 |
| Atherosclerosis | ||||||
| Cases | 54 | 18 | 17 | 32 | ||
| HR‡ (95% CI) | 1 | 1.61 (0.88 to 2.95) | 1.10 (0.62 to 1.95) | 1.03 (0.64 to 1.67) | 0.35 | 0.38 |
| Cerebrovascular diseases | ||||||
| Cases | 541 | 190 | 179 | 233 | ||
| HR‡ (95% CI) | 1 | 1.19 (0.96 to 1.48) | 1.12 (0.92 to 1.36) | 0.98 (0.80 to 1.19) | 0.45 | 0.49 |
*Test for linear trend calculated by entering cumulative exposure as a continuous variable in the model.
†Test for linear trend calculated by entering cumulative exposure as a continuous variable in the model among ever low- and high-exposed subjects only.
‡Adjusted for age at baseline, sex, smoking, attained education level, alcohol consumption and body mass index.