• *Of these patients, 99% had associated distal DVT
  • Reference [7]
DVT location in 189 patients diagnosed with venography
Location of DVT % of patients
Proximal DVT 88%*
Isolated distal DVT 12%

  • Reference [7]
DVT location in 166 patients with a proximal DVT diagnosed by venography
Location of DVT % of patients
Popliteal 10%
Popliteal and femoral 42%
Popliteal, femoral, and common femoral 5%
All proximal veins 35%
Common femoral +/- femoral or iliac 8%










- If both legs are symptomatic, use more symptomatic leg
- Reference 4
Finding/History Points
Active cancer (treatment ongoing, administered
within previous 6 months or palliative)
+1
Paralysis or recent immobilization
of the lower extremity
+1
Recently bedridden for ≥ 3 days, or
major surgery within previous 12 weeks
+1
Localized tenderness along distribution
of deep vein system
+1
Swelling of entire leg +1
Calf swelling ≥ 3 cm larger than
that of the unaffected leg
(measured 10 cm below the tibial tuberosity)
+1
Pitting edema confined to affected leg +1
Dilated superficial veins
on affected leg (nonvaricose)
+1
Previously documented DVT +1
Alternative diagnosis at
least as probable as DVT
-2


Reference 4
Wells Score DVT probability
≤ 0 Low probability
1 - 2 Moderate probability
≥ 3 High probability








  • ** Provoked - recent surgery or transient, nonsurgical risk factor
  • ACCP does not recommend anticoagulation in certain distal DVTs (see distal DVT recs above)
  • Reference 10
ACCP recommendations for extended anticoagulation after 3 months of anticoagulation
provoked vs
unprovoked**
Proximal vs
distal
(see location above)
First vs
second
Bleeding risk
(see bleeding risk below)
Extended anticoagulation
recommended
provoked proximal and distal not specified any no
unprovoked proximal first low or moderate yes
unprovoked proximal first high no
unprovoked proximal second low or moderate yes
unprovoked proximal second high no
unprovoked distal first any no
unprovoked distal second low or moderate yes
unprovoked distal second high no
Active cancer - ACCP recommends extended anticoagulation in all patients with active cancer



Reference 11
Type of VTE Recurrence rate in first year after
treatment of initial VTE
(with no extended anticoagulation)
Provoked by surgery 1.0%
Provoked by nonsurgical
risk factor
5.8%
Unprovoked VTE 7.9%





Estimated effect over 5 years of treatment with anticoagulation (% are absolute changes)
Low bleeding risk* Intermediate bleeding risk* High bleeding risk*
First VTE provoked by surgery Recurrent VTE reduction ↓ 2.6% ↓ 2.6% ↓ 2.6%
Major bleeding increase ↑ 2.4% ↑ 4.9% ↑ 19.6%
First VTE provoked by a nonsurgical factor/
first unprovoked distal DVT
Recurrent VTE reduction ↓ 13.2% ↓ 13.2% ↓ 13.2%
Major bleeding increase ↑ 2.4% ↑ 4.9% ↑ 19.6%
First unprovoked proximal DVT or PE Recurrent VTE reduction ↓ 26.4% ↓ 26.4% ↓ 26.4%
Major bleeding increase ↑ 2.4% ↑ 4.9% ↑ 19.6%
Second unprovoked VTE Recurrent VTE reduction ↓ 39.6% ↓ 39.6% ↓ 39.6%
Major bleeding increase ↑ 2.4% ↑ 4.9% ↑ 19.6%