Positive predictive values of venous thromboembolism diagnoses in the Danish National Patient Registry, by diagnostic modalities during admission
| Number of patients sampled | Confirmed diagnoses/ available records | Positive predictive value, % (95% CI) | |
|---|---|---|---|
| First-time venous thromboembolism | 100 | 87/99 | 88 (80 to 93) |
| No ultrasound or CT scan during admission | 22 | 17/22 | 77 (57 to 90) |
| Ultrasound or CT scan during admission | 77 | 70/77 | 91 (82 to 96) |
| Ultrasound and CT scan during admission | 13 | 13/13 | 100 (77 to 100) |
| Recurrent venous thromboembolism | 100 | 67/93 | 72 (62 to 80) |
| No ultrasound or CT scan during admission | 25 | 11/25 | 44 (27 to 63) |
| Ultrasound or CT scan during admission | 72 | 56/68 | 82 (72 to 90) |
| Ultrasound and CT scan during admission | 7 | 5/7 | 71 (36 to 92) |