Rates of hemorrhage by length of time since starting warfarin therapy
| Characteristic | Hemorrhages during 5-yr follow-up, no. (%)* | Rate of hemorrhage, % per person-year (95% CI) | ||
|---|---|---|---|---|
| First 30 d | Remainder of 5-yr follow-up | Overall | ||
| Overall, no. | 10 840 | 11.8 (11.1–12.4) | 3.4 (3.4–3.5) | 3.8 (3.8–3.9) |
| CHADS2 score | ||||
| 0 | 382 (3.5) | 7.2 (5.5–9.5) | 1.6 (1.4–1.7) | 1.8 (1.6–2.0) |
| 1 | 1 845 (17.0) | 7.3 (6.3–8.4) | 2.3 (2.2–2.4) | 2.5 (2.4–2.6) |
| 2–3 | 7 053 (65.1) | 13.3 (12.5–14.3) | 3.8 (3.7–3.9) | 4.3 (4.2–4.4) |
| 4–6 | 1 560 (14.4) | 16.7 (14.3–19.4) | 6.0 (5.7–6.3) | 6.7 (6.3–7.0) |
| Type of hemorrhage | ||||
| Intracranial | 549 (5.1) | 0.4 (0.4–0.5) | 0.2 (0.2–0.2) | 0.2 (0.2–0.2) |
| Upper gastrointestinal | 2 829 (26.1) | 4.0 (3.8–4.2) | 0.9 (0.8–0.9) | 1.0 (1.0–1.0) |
| Lower gastrointestinal | 3 956 (36.5) | 4.6 (4.4–4.9) | 1.2 (1.2–1.3) | 1.4 (1.4–1.4) |
| Other | 4 190 (38.7) | 4.7 (4.5–5.0) | 1.3 (1.3–1.3) | 1.5 (1.5–1.5) |
| Age ≤ 75 yr, no. | 3684 | 9.2 (8.4–10.2) | 2.6 (2.5–2.7) | 2.9 (2.8–3.0) |
| CHADS2 score | ||||
| 0 | 382 (10.4) | 7.2 (5.5–9.5) | 1.6 (1.4–1.7) | 1.8 (1.6–2.0) |
| 1 | 1 204 (32.7) | 6.8 (5.7–8.1) | 2.0 (1.9–2.2) | 2.3 (2.1–2.4) |
| 2–3 | 1 881 (51.1) | 12.1 (10.6–13.9) | 3.4 (3.3–3.6) | 3.9 (3.7–4.0) |
| 4–6 | 217 (5.9) | 13.1 (8.2–20.7) | 5.5 (4.8–6.4) | 6.0 (5.3–6.9) |
| Type of hemorrhage | ||||
| Intracranial | 194 (5.3) | 0.4 (0.3–0.4) | 0.1 (0.1–0.1) | 0.2 (0.1–0.2) |
| Upper gastrointestinal | 1 055 (28.6) | 3.9 (3.5–4.3) | 0.7 (0.7–0.7) | 0.8 (0.8–0.9) |
| Lower gastrointestinal | 1 268 (34.4) | 3.5 (3.2–3.9) | 0.9 (0.9–0.9) | 1.0 (1.0–1.0) |
| Other | 1 406 (38.2) | 3.3 (3.0–3.7) | 1.0 (1.0–1.0) | 1.1 (1.1–1.1) |
| Age > 75 yr, no. | 7 156 | 13.7 (12.7–14.6) | 4.1 (4.0–4.2) | 4.6 (4.5–4.7) |
| CHADS2 score | ||||
| 0 | 0 (0.0) | — | — | — |
| 1 | 641 (9.0) | 8.5 (6.6–10.9) | 2.8 (2.6–3.1) | 3.1 (2.9–3.4) |
| 2–3 | 5 172 (72.3) | 13.8 (12.8–15.0) | 4.0 (3.9–4.1) | 4.5 (4.4–4.6) |
| 4–6 | 1 343 (18.8) | 17.3 (14.6–20.3) | 6.1 (5.7–6.4) | 6.8 (6.4–7.1) |
| Type of hemorrhage | ||||
| Intracranial | 355 (5.0) | 0.5 (0.4–0.5) | 0.2 (0.2–0.2) | 0.2 (0.2–0.2) |
| Upper gastrointestinal | 1 774 (24.8) | 4.1 (3.8–4.3) | 1.0 (1.0–1.0) | 1.1 (1.1–1.2) |
| Lower gastrointestinal | 2 688 (37.6) | 5.5 (5.1–5.9) | 1.5 (1.5–1.6) | 1.7 (1.7–1.8) |
| Other | 2 784 (38.9) | 5.7 (5.3–6.1) | 1.6 (1.5–1.6) | 1.8 (1.8–1.8) |
Note: CI = confidence interval.
↵* Unless otherwise indicated