Thrombus a prospective, multicentre study: diagnostic concordance of emergency doctor-performed bedside ultrasonography versus specialist-performed echo-doppler ultrasonography, in standard clinical practice, in the diagnosis of deep venous thrombosis of

Introduction: Deep venous thrombosis (DVT) is an increasing cause of morbidity and mortality. Current evidence suggest that Emergency doctors can perform Bedside Ultrasound (EUS) to diagnose DVT, in a quick, inexpensive and accurate way in comparison with “gold standard” studies by the specialist doctor-performed Doppler Ultrasound (SDUS). Nonetheless, important concerns have been raised about the interpretation of these studies: small sample sizes, very different experience of the emergency doctors performing, highly skilled and lack of details involving patient enrolment Objectives: To ascertain the diagnostic concordance of a homogeneous group of novice emergency doctor performing EUSof the lower extremities, with SDUS in the diagnosis of DVT, in routine clinical practice. Methods: In this prospective, multicenter study, adult patients (>18 years old) with clinical suspicion of DVT, with high or moderate risk (on Wells scoring) or low risk with increased D-dimer levels, were eligible. From September 2013 to September 2014, 328 patients were enrolled. Fifty-one investigators from seven hospitals performed the EUS. Each patient had the EUS and SDUS both in femoral and popliteal areas. The final result was considered non-concordant if one or both of the EUS did not match with the SDUS. For inter-rater agreement analysis, we used the Kappa statistic, and confidence intervals (CIs) of 95% were computed using a jack-knife re-sampling procedure. Results: Of 326 ultrasound studies, 35 were discordant. The percentage of agreement between EUS and SDUS was 89%. The kappa index was 0.76 (95% CI = 0.69–0.84), which means a “substantial agreement.” Thorough study of the mismatched EUS/ SDUS performances, revealed that: - 56% of non-concordant results were in the first two performances. - 83% occurred in the first five performances. Conclusions: There is “substantial agreement” between the EUS and SDUS in the diagnosis of DVT in routine clinical practice. Thorough examination of the THROMBUS data, suggests that it seems quite reasonable (if not mandatory), that Emergency doctors performing US in the diagnosis of DVT should be shadowed by senior staff experienced in US, at least during their first five performances.This will decrease the mismatch in relation to SDUS (from 89% to 95%).