Relative risk of venous thromboembolism according to the activated partial thromboplastin time (APTT) ratio using as cut-off value the fifth percentile of the distribution of values in controls
APTT ratio* . | Patients N = 193 . | Controls N = 259 . | Odds ratio†(95% CI) . | Odds ratio‡(95% CI) . |
|---|---|---|---|---|
| Greater than or equal to 0.87 | 165 | 243 | 1 | 1 |
| Less than 0.87 | 28 | 16 | 2.7 (1.4-5.3) | 2.1 (1.0-4.2) |
APTT ratio* . | Patients N = 193 . | Controls N = 259 . | Odds ratio†(95% CI) . | Odds ratio‡(95% CI) . |
|---|---|---|---|---|
| Greater than or equal to 0.87 | 165 | 243 | 1 | 1 |
| Less than 0.87 | 28 | 16 | 2.7 (1.4-5.3) | 2.1 (1.0-4.2) |
The analysis is represented in the table refers to the patients and controls for whom factor VIII levels and blood group were available.
Test-to-reference coagulation time
Adjusted for age, sex, and the presence of inherited thrombophilia (antithrombin, protein C, and protein S deficiencies, factor V G1691A, and prothrombin G20210A gene mutations). CI indicates confidence interval
Adjusted for age, sex, the presence of inherited thrombophilia, factor VIII levels greater than 171 IU/dL (ninety-fifth percentile of the distribution of the values in controls), and blood group