Dronkers et al developed the I-DVT score for the diagnosis of acute deep vein thrombosis. This can help guide additional testing that can establish the diagnosis. The authors are from Leiden University, Diakonessenhuis Hospital and Alrijne Hospital in The Netherlands.
Patient selection: suspected deep vein thrombosis
Parameters:
(1) immobilization (I) - recently bedridden for > 3 days and/or major surgery within past 4 weeks
(2) difference in diameter (D) - difference in circumference >= 3 cm at a point 10 cm below the tibial tuberosity
(3) history of venous thromboembolism (V)
(4) active malignant tumor (T) - ongoing treatment, within previous 6 months, palliative care
|
Parameter
|
Finding
|
Points
|
|
immobilization
|
no
|
0
|
|
|
yes
|
1
|
|
difference in diameter
|
no
|
0
|
|
|
yes
|
1
|
|
history of venous thromboembolism
|
no
|
0
|
|
|
yes
|
1
|
|
active malignancy
|
no
|
0
|
|
|
yes
|
1
|
Supplemental Parameters:
(5) DVT more likely than alternative diagnosis
(6) use of oral contraceptives
|
Parameter
|
Finding
|
Points
|
|
DVT most likely diagnosis
|
no
|
0
|
|
|
yes
|
1
|
|
use of oral contraceptive
|
no
|
0
|
|
|
yes
|
1
|
total I-DVT score =
= SUM(points for the first 4 parameters)
adjusted I-DVT score =
= SUM(points for the first 4 parameters) + (points for the 2 supplemental parameters)
Interpretation:
• minimum scores: 0
• maximum I-DVT score: 4
• maximum adjusted I-DVT score: 6
• An I-DVT score >= 1 or an adjusted I-DVT score >= 3 indicate that a deep vein thrombosis is likely.
Management:
(1) A D-dimer is done if DVT is unlikely or if ultrasonography is negative.
(2) Ultrasonography is done if DVT is likely or D-dimer is positive.
(3) Treatment is started if ultrasonography is positive.
(4) Follow-up is performed at 3 months.
Performance:
• The area under the ROC curve is 0.65 versus 0.70 for the Wells score.
