2009 Evidence-based clinical practice guidelines for diagnosing first episodes of lower extremities deep vein thrombosis in ambulatory outpatients

INTRODUCTION: The GRADE working group has recently suggested a rigorous framework for clinical practice guidelines (CPG) addressing diagnostic tests and test strategies based on the impact of alternative approaches on patient-important outcomes. The framework mandates explicit evidence summaries, ratings of the quality of evidence, and specifying recommendations as strong or weak. OBJECTIVES: To test the feasibility and performance of the GRADE approach, we applied this framework to well-researched issues in the diagnoses of deep venous thrombosis (DVT). METHODS: After identifying pertinent clinical questions, we searched existing CPG and systematic reviews for relevant studies. We summarized the data in form of evidence tables and developed recommendations including, when needed, a formal consensus process. RESULTS AND CONCLUSIONS: We provide three groups of recommendations for clinicians practicing in settings with access to different types of D-dimer tests - highly sensitive, moderately sensitive, and no availability of D-dimer. We consider the use of clinical prediction rules in guiding the diagnostic process, the potential for negative D-dimer or venous ultrasound (US) to rule out disease, and the role of follow-up testing (US following positive D-dimer result, D-dimer following negative US, and serial US) depending on the probability of DVT at the start of diagnostic process. We recommend the following: that clinicians without access to a highly or moderately sensitive D-dimer test rely on US to guide DVT diagnosis; that those with access use the highly sensitive D-dimer to determine, in patients with low or moderate probability of DVT (by the Wells rule) whether US is needed; that in patients with low pre-test probability (pre-TP) and a negative D-dimer (either highly or moderately sensitive) they follow patients without further testing; that in patients with high pre-test probability they perform a compression ultrasound without D-dimer testing. Copyright by Medycyna Praktyczna, 2009.