Table 4.
Adjusted Hazard Ratios for Primary End point or Major Hemorrhage and Components, According to Age Subgroup
| Warfarin |
Aspirin |
Adjusted Hazard Ratio (95% CI) for Warfarin vs Aspirin |
P Value |
||||
|---|---|---|---|---|---|---|---|
| Events, % | Rate* | Events, % | Rate* | For HR† | For Interaction‡ | ||
| <60 y | n=508 | 1903.7 pt-years | n=522 | 1904.1 pt-years | |||
| Primary plus hemorrhage | 103 (20.3) | 5.41 | 138 (26.4) | 7.25 | 0.68 (0.52–0.89) | 0.005 | <0.001 |
| Major hemorrhage | 13 (2.6) | 0.68 | 12 (2.3) | 0.63 | 0.98 (0.42–2.27) | 0.96 | 0.06 |
| Ischemic stroke | 12 (2.4) | 0.63 | 25 (4.8) | 1.31 | 0.50 (0.31–0.81) | 0.005 | 0.68§ |
| Intracerebral hemorrhage | 2 (0.4) | 0.11 | 0 (0.0) | 0.00 | 2.05 (0.36–11.52) | 0.42 | …∥ |
| Death | 76 (15.0) | 3.99 | 101 (19.3) | 5.30 | 0.66 (0.48–0.90) | 0.009 | 0.002 |
| ≥60 y | n=634 | 2026.2 pt-years | n=641 | 2085.9 pt-years | |||
| Primary plus hemorrhage | 239 (37.7) | 11.8 | 195 (30.4) | 9.35 | 1.25 (1.02–1.53) | 0.03 | <0.001 |
| Major hemorrhage | 48 (7.6) | 2.37 | 17 (2.7) | 0.82 | 2.67 (1.48–4.81) | 0.001 | 0.06 |
| Ischemic stroke | 16 (2.5) | 0.79 | 29 (4.5) | 1.39 | 0.50 (0.31–0.81) | 0.005 | 0.68§ |
| Intracerebral hemorrhage | 2 (0.3) | 0.10 | 2 (0.3) | 0.10 | 2.05 (0.36–11.52) | 0.42 | …∥ |
| Death | 173 (27.3) | 8.54 | 147 (22.9) | 7.05 | 1.22 (0.96–1.56) | 0.009 | 0.002 |
6MW indicates 6-minute walk; BMI, body mass index; BUN, blood urea nitrogen; CI, confidence interval; DBP, diastolic blood pressure; HR, hazard ratio; ICH, intracerebral hemorrhage; NYHA, New York Heart Association; and PVD, peripheral vascular disease.
Rates are per 100 patient-years.
From Cox models stratified by site, prior stroke status, and NYHA classification. HRs for composite end point, death, stroke, and hemorrhage are adjusted for age category, sex, diabetes mellitus, PVD, BMI, BUN, ejection fraction, DBP, 6MW, and hemoglobin. HRs for ICH are adjusted for age category.
Treatment-by-age category interaction terms are included as applicable.
Hazard ratios presented are from models without treatment×age category interaction term for ischemic stroke, because there was no evidence of treatment×age category interaction.
Not enough information to test for interaction. The HR presented is from the model without a treatment×age category term.