Table 1

Positive predictive values of venous thromboembolism diagnoses in the Danish National Patient Registry, by diagnostic modalities during admission

Number of patients sampledConfirmed diagnoses/ available recordsPositive predictive value, % (95% CI)
First-time venous thromboembolism10087/9988 (80 to 93)
 No ultrasound or CT scan during admission2217/2277 (57 to 90)
 Ultrasound or CT scan during admission7770/7791 (82 to 96)
 Ultrasound and CT scan during admission1313/13100 (77 to 100)
Recurrent venous thromboembolism10067/9372 (62 to 80)
 No ultrasound or CT scan during admission2511/2544 (27 to 63)
 Ultrasound or CT scan during admission7256/6882 (72 to 90)
 Ultrasound and CT scan during admission75/771 (36 to 92)