Recurrence rates of venous thrombosis in women with a nonhormonal versus hormonal first event
| . | Nonhormonal first venous thrombosis . | Hormonal first venous thrombosis . |
|---|---|---|
| No. of subjects | 273 | 201 |
| Mean age at onset of first event, y | 40 | 30‡ |
| No. of recurrences* | 81 | 68 |
| Mean age onset recurrent event, y | 47 | 40§ |
| Observation period, y | 1604 | 2074 |
| Annual incidence, % (95% CI) | 5.1 (4.0-6.3) | 3.3 (2.5-4.2) |
| Crude relative risk (95% CI) | Reference | 0.6 (0.5-0.9) |
| Adjusted relative risk (95% CI)† | Reference | 0.7 (0.5-0.97) |
| . | Nonhormonal first venous thrombosis . | Hormonal first venous thrombosis . |
|---|---|---|
| No. of subjects | 273 | 201 |
| Mean age at onset of first event, y | 40 | 30‡ |
| No. of recurrences* | 81 | 68 |
| Mean age onset recurrent event, y | 47 | 40§ |
| Observation period, y | 1604 | 2074 |
| Annual incidence, % (95% CI) | 5.1 (4.0-6.3) | 3.3 (2.5-4.2) |
| Crude relative risk (95% CI) | Reference | 0.6 (0.5-0.9) |
| Adjusted relative risk (95% CI)† | Reference | 0.7 (0.5-0.97) |
Hormonal event indicates venous thrombosis associated with oral contraception, pregnancy or puerperium, or hormonal replacement therapy.
CI indicates confidence interval.
Recurrences associated with hormonal risk factors were excluded.
Adjusted for antithrombin, protein C, and protein S deficiency.
P < .001
P = .003.