Rodger 2008 HERDOO2 after a first unprovoked VTE. Score 1 each for hyperpigmentation, edema, or redness in either leg; D-dimer ≥250 μg/L while on anticoagulants; BMI ≥30; age ≥65 (equality scores). Max 4. low_risk is true only for women with score ≤1. Men have no low-risk subgroup in the derivation. Not a medical device and not a duration-of-anticoagulation order.

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