| Characteristics | Aspirin(N = 18 652) | Placebo(N = 18 618) | p Value |
| Mean (SD) age (years) | 54.7 (7.1) | 54.7 (7.1) | 0.83 |
| Mean (SD) BMI (kg/m2) | 26.0 (5.0) | 25.9 (5.0) | 0.39 |
| BMI ⩾30 kg/m2 (%) | 17.7 | 17.6 | 0.71 |
| History of hypertension (%) | 25.7 | 25.4 | 0.51 |
| History of diabetes (%) | 2.7 | 2.4 | 0.15 |
| Smoking status (%) | |||
| Never | 51.2 | 51.2 | 0.61 |
| Past | 35.7 | 35.5 | |
| Current (<15 cigs/day) | 4.8 | 5.0 | |
| Current (15+ cigs/day) | 8.2 | 8.4 | |
| Exercise (%) | |||
| Rarely | 38.3 | 38.1 | 0.51 |
| <1/week | 19.5 | 20.3 | |
| 1–3/week | 31.4 | 31.1 | |
| ⩾4/week | 10.9 | 10.5 | |
| Alcohol consumption (%) | |||
| Rarely | 44.8 | 45.1 | 0.79 |
| 1–3/month | 13.4 | 12.8 | |
| 1–6/week | 31.6 | 31.8 | |
| ⩾1/day | 10.2 | 10.3 | |
| Postmenopausal | 55.0 | 54.4 | 0.23 |
| Postmenopausal hormone use | |||
| Never | 50.0 | 50.4 | 0.27 |
| Past | 9.0 | 9.2 | |
| Current | 41.0 | 40.4 |
BMI, body mass index.