{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"wells-score-dvt"},"result":{"entity_type":"calculator","id":"wells-score-dvt","calculator_id":"wells-score-dvt","canonical_url":"https://tttkmbb.com/medical/wells-score-dvt","name":"Wells Score for DVT Calculator","title":"Wells Score for Deep Vein Thrombosis – Pretest Probability (Wells 1997 and 2003 Criteria)","category":"medical","category_name":"Medical & Clinical","tool_name":"calculate_wells_dvt_score","featured_mcp_tool":false,"description":"Sums the Wells clinical criteria for suspected deep vein thrombosis and reports the three-tier (low/moderate/high) and two-tier (unlikely/likely) pretest probability categories.","use_when":"You are structuring the pretest probability of a first lower-limb DVT before D-dimer testing or ultrasound.","do_not_use_when":"Suspected pulmonary embolism (the Wells PE score differs), pregnancy, or upper-limb DVT, where the score was not validated.","inputs":[{"name":"active_cancer","label":"Active cancer (treatment within 6 months or palliative)","type":"boolean","required":false,"default":false,"description":"+1 point.","example":true},{"name":"paralysis_or_immobilisation","label":"Paralysis, paresis or recent plaster immobilisation of a leg","type":"boolean","required":false,"default":false,"description":"+1 point.","example":false},{"name":"bedridden_or_major_surgery","label":"Bedridden >3 days or major surgery within 12 weeks","type":"boolean","required":false,"default":false,"description":"+1 point.","example":false},{"name":"localised_tenderness","label":"Localised tenderness along the deep venous system","type":"boolean","required":false,"default":false,"description":"+1 point.","example":true},{"name":"entire_leg_swollen","label":"Entire leg swollen","type":"boolean","required":false,"default":false,"description":"+1 point.","example":false},{"name":"calf_swelling_over_3cm","label":"Calf swelling >3 cm vs the other leg (10 cm below tibial tuberosity)","type":"boolean","required":false,"default":false,"description":"+1 point.","example":true},{"name":"pitting_oedema","label":"Pitting oedema confined to the symptomatic leg","type":"boolean","required":false,"default":false,"description":"+1 point.","example":false},{"name":"collateral_superficial_veins","label":"Collateral (non-varicose) superficial veins","type":"boolean","required":false,"default":false,"description":"+1 point.","example":false},{"name":"previous_dvt","label":"Previously documented DVT","type":"boolean","required":false,"default":false,"description":"+1 point (added in the 2003 modification).","example":false},{"name":"alternative_diagnosis_likely","label":"Alternative diagnosis at least as likely as DVT","type":"boolean","required":false,"default":false,"description":"−2 points.","example":false}],"outputs":[{"name":"score","label":"Wells score","type":"integer","decimals":4,"description":"Sum of the criteria (−2 to 9)."},{"name":"three_tier_probability","label":"Three-tier probability (Wells 1997)","type":"string","decimals":4,"description":"Low (≤0, about 3% DVT prevalence), moderate (1–2, about 17%) or high (≥3, about 75%)."},{"name":"two_tier_category","label":"Two-tier category (Wells 2003)","type":"string","decimals":4,"description":"DVT unlikely (≤1) or DVT likely (≥2)."},{"name":"criteria_met","label":"Criteria met","type":"string_list","decimals":4,"description":"Criteria that contributed to the score."}],"input_schema":{"type":"object","properties":{"active_cancer":{"description":"+1 point.","type":"boolean","default":false,"examples":[true]},"paralysis_or_immobilisation":{"description":"+1 point.","type":"boolean","default":false,"examples":[false]},"bedridden_or_major_surgery":{"description":"+1 point.","type":"boolean","default":false,"examples":[false]},"localised_tenderness":{"description":"+1 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75%).","type":"string"},"two_tier_category":{"description":"DVT unlikely (≤1) or DVT likely (≥2).","type":"string"},"criteria_met":{"description":"Criteria that contributed to the score.","type":"array","items":{"type":"string"}}}},"formula":"score = Σ positive criteria (1 point each) − 2 if an alternative diagnosis is at least as likely; low ≤ 0, moderate 1–2, high ≥ 3; unlikely ≤ 1, likely ≥ 2","method":"Prevalence figures come from the 1997 derivation cohort; in the 2003 two-tier study a low score with a negative D-dimer safely excluded DVT without ultrasound. Results are informational only and not a substitute for clinical judgement or medical advice.","sources":[{"name":"Wells PS et al. (1997) Value of assessment of pretest probability of deep-vein thrombosis in clinical management, Lancet 350:1795-1798","url":"https://pubmed.ncbi.nlm.nih.gov/9428249/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"Wells PS et al. (2003) Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis, N Engl J Med 349:1227-1235","url":"https://pubmed.ncbi.nlm.nih.gov/13679527/","type":"peer_reviewed","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"Active cancer, calf swelling, localised tenderness","inputs":{"active_cancer":true,"calf_swelling_over_3cm":true,"localised_tenderness":true},"expected":{"score":3,"three_tier_probability":"High (score ≥3; about 75% DVT prevalence)","two_tier_category":"DVT likely (score ≥2)"},"url":"https://tttkmbb.com/api/v1/calculate/wells-score-dvt?active_cancer=true&calf_swelling_over_3cm=true&localised_tenderness=true"},{"name":"Entire leg swollen, alternative diagnosis likely","inputs":{"entire_leg_swollen":true,"alternative_diagnosis_likely":true},"expected":{"score":-1,"three_tier_probability":"Low (score ≤0; about 3% DVT prevalence)","two_tier_category":"DVT unlikely (score ≤1)"},"url":"https://tttkmbb.com/api/v1/calculate/wells-score-dvt?entire_leg_swollen=true&alternative_diagnosis_likely=true"}],"faq":[{"q":"What do I do with the category?","a":"In the validated pathway, 'unlikely' plus a negative D-dimer excludes DVT; 'likely' or a positive D-dimer proceeds to compression ultrasound."},{"q":"Which version is this?","a":"The 2003 modified criteria (including previously documented DVT); the three-tier output uses the 1997 cut-offs, so both categorisations are shown."}],"tags":["wells score","dvt","deep vein thrombosis","pretest probability","d-dimer"],"related":[{"calculator_id":"cha2ds2-vasc-score","reason":"Another clinical risk score with anticoagulation implications."},{"calculator_id":"bmi","reason":"Obesity is a background risk factor for venous thrombosis."}],"links":{"html":"https://tttkmbb.com/medical/wells-score-dvt","markdown":"https://tttkmbb.com/medical/wells-score-dvt.md","json":"https://tttkmbb.com/medical/wells-score-dvt.json","api":"https://tttkmbb.com/api/v1/calculate/wells-score-dvt","schema":"https://tttkmbb.com/api/v1/calculators/wells-score-dvt","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:50:28Z"}