Current diagnosis of venous thromboembolism in primary care: a clinical practice guideline from the American Academy of Family Physicians and the American College of Physicians. Ann Intern Med

This guideline summarizes the current approaches for the diagnosis of venous thromboembolism. The importance of early diagnosis to prevent mortality and morbidity associated with venous thromboembolism cannot be overstressed. This fi eld is highly dynamic, however, and new evidence is emerging periodically that may change the recommendations. The purpose of this guideline is to present recommendations based on current evidence to clinicians to aid in the diagnosis of lower extremity deep venous thrombosis and pulmonary embolism. Ann Fam Med 2007;5:57-62. DOI: 10.1370/afm.667. RECOMMENDATIONS Recommendation 1 Validated clinical prediction rules should be used to estimate pretest probability of venous thromboembolism (VTE), both deep venous thrombosis (DVT) and pulmonary embo-lism, and for the basis of interpretation of subsequent tests. Good quality evidence supports the use of clinical prediction rules to establish pretest probability of disease. The Wells prediction rules for DVT and for pulmonary embolism (Tables 1 and 2) have been validated and are frequently used to estimate the probability of VTE before per-forming more defi nitive testing on patients. The Wells prediction rule performs better in younger patients without comorbidities or a history of VTE than it does in other patients. Physicians should use their clinical judgment in cases where a patient is older or presents with comorbidities. Recommendation 2 In appropriately selected patients with low pretest probability of DVT or pulmonary embolism, obtaining a high-sensitivity D-dimer is a reasonable option, and if negative