Wells Clinical Prediction Rule for Deep Vein Thrombosis (DVT)

Wells Clinical Prediction Rule for DVT [link url="//soapnote.org/blood-lymph/wells-clinical-prediction-rule-for-pulmonary-embolism/" memo="see also - Wells PE calculator"]
Clinical Features:
[select name="variable_1" value="No (0 points)=0|Yes (1 point)=1"] <-- Active cancer (treatment within 6 months, or palliation)?
[select name="variable_2" value="No (0 points)=0|Yes (1 point)=1"] <-- Bedridden for more than 3 days because of surgery (within 4 weeks)?
[select name="variable_3" value="No (0 points)=0|Yes (1 point)=1"] <-- Localized tenderness along distribution of deep veins?
[select name="variable_4" value="No (0 points)=0|Yes (1 point)=1"] <-- Entire leg swollen?
[select name="variable_5" value="No (0 points)=0|Yes (1 point)=1"] <-- Unilateral calf swelling of greater than 3 cm (below tibial tuberosity)?
[select name="variable_6" value="No (0 points)=0|Yes (1 point)=1"] <-- Unilateral pitting edema?
[select name="variable_7" value="No (0 points)=0|Yes (1 point)=1"] <-- Collateral superficial veins?
[select name="variable_8" value="No (0 points)=0|Yes (-2 points)=-2"] <-- Alternative diagnosis as likely as or more likely than DVT?
Score: [calc value="score=(variable_1)+(variable_2)+(variable_3)+(variable_4)+(variable_5)+(variable_6)+(variable_7)+(variable_8)" memo="Number"] out of 7
Risk --> [calc value="score=(variable_1)+(variable_2)+(variable_3)+(variable_4)+(variable_5)+(variable_6)+(variable_7)+(variable_8);score>2?'High Risk (75%)':score>0?'Moderate Risk (17%)':'Low Risk (3%)'" memo="Interpretation"]
[checkbox memo="display/hide references" name="footnotes" value=""][conditional field="footnotes" condition="(footnotes).is('')"]
reference:
[link url="//www.ncbi.nlm.nih.gov/pubmed/9428249" memo="#1"] Wells (1997) Lancet 350:1795-8
[link url="//www.aafp.org/afp/2004/0615/p2829.html" memo="#2"] Ramzi (2004) Am Fam Physician 69:2829-36[/conditional]