Risk of VTE according to the number with thromboses in the family
| Number with VTE in the family* . | Number of families, n . | Number of included FDR, n . | Size of families, mean (SD) . | Annual incidence of VTE in FDR, percentage 100 person-years (95% CI) . | Adjusted OR, estimate (95% CI)† . | P . |
|---|---|---|---|---|---|---|
| 1 | 405 | 1998 | 7.8 (3.0) | 0.41 (0.37-0.45) | Reference | <.001 |
| 2 | 82 | 462 | 8.1 (3.3) | 0.79 (0.68-0.92) | 2.47 (1.98-3.09) | <.001 |
| 3 | 19 | 145 | 9.7 (3.1) | 0.88 (0.67-1.13) | 3.54 (2.49-5.04) | <.001 |
| 4 | 1 | 12 | 15 | 0.75 (0.18-1.60) | 5.17 (1.55-17.28) | <.001 |
| ≥2 | 102 | 619 | 8.5 (3.3) | 0.81 (0.70-0.91) | 2.71 (2.22-3.31) | <.001 |
| Number with VTE in the family* . | Number of families, n . | Number of included FDR, n . | Size of families, mean (SD) . | Annual incidence of VTE in FDR, percentage 100 person-years (95% CI) . | Adjusted OR, estimate (95% CI)† . | P . |
|---|---|---|---|---|---|---|
| 1 | 405 | 1998 | 7.8 (3.0) | 0.41 (0.37-0.45) | Reference | <.001 |
| 2 | 82 | 462 | 8.1 (3.3) | 0.79 (0.68-0.92) | 2.47 (1.98-3.09) | <.001 |
| 3 | 19 | 145 | 9.7 (3.1) | 0.88 (0.67-1.13) | 3.54 (2.49-5.04) | <.001 |
| 4 | 1 | 12 | 15 | 0.75 (0.18-1.60) | 5.17 (1.55-17.28) | <.001 |
| ≥2 | 102 | 619 | 8.5 (3.3) | 0.81 (0.70-0.91) | 2.71 (2.22-3.31) | <.001 |
Includes the families of index cases with provoked VTE (n = 138) and unprovoked VTE (n = 369).
CI, confidence interval; FDR, first-degree relatives; OR, odds ratio; SD, standard deviation; VTE, venous thromboembolism.
Includes the index case; therefore, all families had at least a single person with VTE.
Adjusted for age during the observation period and the number of members in each family.