Recurrence rates of venous thrombosis in women with an idiopathic first event versus oral contraceptives or hormonal replacement therapy–associated event
| . | Unprovokedvenous thrombosis* . | Oral contraceptivevenous thrombosis† . |
|---|---|---|
| No. of subjects | 122 | 109 |
| No. of recurrences† | 46 | 29 |
| Mean age onset recurrent event, y | 49 | 32§ |
| Observation period, y | 615 | 679 |
| Annual incidence, % (95% CI) | 7.5 (5.5-10.0) | 4.3 (2.9-6.1) |
| Crude relative risk (95% CI) | Reference | 0.6 (0.4-0.96) |
| Adjusted relative risk (95% CI)‡ | Reference | 0.6 (0.4-0.9) |
| . | Unprovokedvenous thrombosis* . | Oral contraceptivevenous thrombosis† . |
|---|---|---|
| No. of subjects | 122 | 109 |
| No. of recurrences† | 46 | 29 |
| Mean age onset recurrent event, y | 49 | 32§ |
| Observation period, y | 615 | 679 |
| Annual incidence, % (95% CI) | 7.5 (5.5-10.0) | 4.3 (2.9-6.1) |
| Crude relative risk (95% CI) | Reference | 0.6 (0.4-0.96) |
| Adjusted relative risk (95% CI)‡ | Reference | 0.6 (0.4-0.9) |
CI indicates confidence interval.
Unprovoked indicates unprovoked first venous thrombosis and unprovoked recurrence.
Oral contraceptive indicates first venous thrombosis associated with oral contraceptives or hormonal replacement therapy, unprovoked recurrence.
Adjusted for antithrombin, protein C, and protein S deficiency.
P < .001.