Prevalence
Clinical
features
Differential
diagnosis
Investigations
Therapy
Prevention
Prognosis
|  | | | Investigations |
High risk for DVT
- Positive scan: DVT
- Negative scan: Venous thromboembolism remains so likely that a
venogram is needed.
- If the venogram is positive: DVT
- If the venogram is negative: no DVT
Moderate risk for DVT
- Positive scan: DVT
- Negative scan: Repeat the scan in one week and withhold
anticoagulation.
- If it is positive: DVT
- If it is negative: no DVT
Low risk for DVT
- Positive scan: Venous thromboembolism remains so unlikely that a
venogram is needed.
- If the venogram is positive: DVT
- If the venogram is negative: no DVT
- Negative scan: no DVT
Why?
An ultrasound scan can help diagnose and exclude a DVT
| Patient |
Target Disorder and
Reference Standard |
Diagnostic Test |
LR+
(95% CI)
|
Post-test Probability |
LR-
(95% CI)
|
Post-test Probability |
suspected DVT
a
(pre-test probability: 16%)
|
deep vein thrombosis
(venogram)
|
ultrasound
|
22
(18 to
28)
|
81% |
0.10
(0.09 to
0.12)
|
2% |
clinical high risk for a DVT
a
(pre-test probability: 75%)
|
|
|
infinity
|
100% |
0.09
|
21% |
clinical moderate risk for a DVT
a
(pre-test probability: 17%)
|
|
|
53
|
92% |
0.39
|
7% |
clinical low risk for a DVT
a
(pre-test probability: 3%)
|
|
|
24
|
43% |
0.34
|
1% |
|
internal medicine