A 60-year-old man referred with suspected deep vein thrombosis (DVT) cut the plantar surface of his left foot on glass 10 days ago and has been resting in bed. He presents with left leg pain and mild calf swelling, redness, and heat. There is no history of a DVT or known family history of venous thromboembolism. Physical examination shows the patient is febrile and has pitting edema of the left calf. The calf erythema is hot, tender, and well demarcated. Enlarged left inguinal lymph nodes are present. He has longstanding diabetes mellitus, and the diagnoses that seem most likely are cellulitis and DVT. Can a clinical probability estimate of DVT reliably determine a pretest probability that can be used in decision making? Continue