Practice patterns surrounding referral to a specialty venous thromboembolism (VTE) clinic: a retrospective review

This study audited prescribing practices for patients with acute venous thromboembolism (VTE) prior to and after being seen in an outpatient VTE clinic. This retrospective chart review conducted between June 2018 through May 2019 included patients with confirmed acute VTE, seen for an initial appointment. Exclusion criteria were patients with additional indications for anticoagulation, lack of information to determine primary outcome and active cancer. To assess practices, the time taken to be seen in clinic, anticoagulant therapies (prior to/following clinic) used and concordance of anticoagulant use with product monographs were assessed. Of the 325 (40.6%) patients included, the median age was 57.7 years, most were referred with pulmonary embolism (PE) (54.5%) and the majority of referrals came through the emergency department (45.2%). The median time to be seen in clinic was 13 days, with no differences in time between type of VTE or proximity of clot. Prior to being seen in VTE clinic, most were prescribed direct oral anticoagulants (DOACs) (81.9%), with a small portion receiving low molecular weight heparin (LMWH) (12.9%) and warfarin (5.2%). Most received anticoagulants concordant with product monographs (87.7%), with more discordance with warfarin (52.9%) and LMWH (14.3%) compared to DOACs (9.4%) (P < 0.001). At the initial VTE clinic visit, 70 (21.5%) patients had therapy changes, with most being from LMWH/warfarin to a DOAC (47.1%). Our data reflects high uptake of DOACs for acute VTE treatment with most prescribed in accordance with product monographs.