Diagnosis

negative D-dimer result excluded DVT in noncancer patients Geersing GJ, Zuithoff NP, Kearon C, et al. Exclusion of deep vein thrombosis using the Wells rule in clinically important subgroups: individual patient data meta-analysis. BMJ. 2014;348:g1340. Clinical impact rating: H Questions What is the accuracy of the Wells rule for excluding deep venous thrombosis (DVT)? What is the accuracy in prespecified subgroups? Methods Design: Individual patient data meta-analysis from 13 studies that included the Wells rule (plus D-dimer testing in 8 studies) and results of a reference test for DVT. Missing data (< 1 % for DVT diagnosis to 5 % for 1 Wells rule variable) were imputed using a multivariate regression technique; missing D-dimer results from 5 studies were not imputed. Prespecified subgroups included active cancer, history of DVT, primary or hospital care setting, and sex