Clinical events that occurred during follow-up in patients who did not resume anticoagulation, in relation to the type of index event and D-dimer results
| Isolated PE | DVT/PE# | p-value | |||||
| D-dimer negative | D-dimer positive | p-value | D-dimer negative | D-dimer positive | p-value | ||
| Overall recurrences¶ n/N (%) (95% CI) | 13/175 (7.4) (4.3–12.9) | 27/458 (5.9) (4.1–8.4) | 0.58 | ||||
| Overall incidence+ n/N (% ppy) (95% CI) | 13/271.4 (4.8) (2.8–8.0) | 27/713.6 (3.8) (2.6–5.4) | 0.47 | ||||
| D-dimer results n (%) | 146 (83.4) | 29 (16.6) | 379 (82.7) | 79 (17.2) | |||
| Total follow-up years | 226.9 | 44.5 | 588.4 | 125.2 | |||
| Recurrences n (%) (95% CI) | 8 (5.5) (2.8–10.4) | 5 (17.2) (7.6–34.5) | 0.0434 | 17 (4.5) (2.8–7.1) | 10 (12.7) (7.0–21.8) | 0.0144 | |
| Incidence % ppy (95% CI) | 3.5 (1.8–6.8) | 11.2 (4.9–23.9) | 0.0575 | 2.9 (1.8–4.6) | 8.0 (4.4–14.0) | 0.0186 | |
| Recurrence rates n/N (%) | |||||||
| Events unprovoked | 6/91 (6.6) | 3/21 (14.3) | 15/283 (5.3) | 6/59 (10.2) | |||
| Events associated with WRF | 2/55 (3.6) | 2/8 (25.0) | 2/96 (2.1) | 4/20 (20.0) | |||
| p-value | 0.71 | 0.62 | 0.26 | 0.45 | |||
| Recurrent events n | |||||||
| Isolated PE | 4 | 2 | 1 | 1 | |||
| DVT/PE | 4 | 3 | 16 | 9 | |||
Note that no death could be attributed to a recurrent thrombotic event. PE: pulmonary embolism; DVT: deep vein thrombosis; % ppy: % per patient-year; WRF: weak risk factor. #: patients included in the D-dimer and ULtrasonography in Combination Italian Study (DULCIS) for an index event of DVT with or without PE; ¶: number of events divided by number of patients; +: number of events divided by number of years.