Assessing Direct Oral Anti-Coagulant And Therapeutic Low Molecular Weight Heparin Prescriptions At A University Teaching Hospital

Abstract

Abstract Background A 2017-2018 survey identified anti-thrombotics as the most commonly implicated agents in reported medication incidents across Irish acute hospitals [State Claims Agency, 2020, Medication Incidents Report (2017-2018)]. Of the top 10 anti-thrombotics reported, 2 were Low Molecular Weight Heparins (LMWHs) and 3 were Direct Oral Anti-Coagulants (DOACs). 3 years after the survey results were published, we audited our hospital's compliance with the Health Service Executive's guidelines for prescribing DOACs and LMWHs. Methods Over 3 consecutive weeks, data was collected by doctors and clinical pharmacists across 6 wards and the intensive and coronary care units. In-patients on a DOAC or therapeutic LMWH were chosen for kardex and laboratory result review. Results 83 patients were included. The average age was 79 years. 81%(n=67) were on a DOAC. 91% were being treated for non-valvular atrial fibrillation (NVAF), 3% for pulmonary embolism (PE), 3% for deep vein thrombosis and 3% had no indication documented. 33%(n=22) had indications for dose reduction but only 77%(n=17) of them were prescribed the appropriate reduced dose. 3%(n=2) had no dose reduction indications but were inappropriately prescribed a reduced dose. 3%(n=2) were on dialysis, 1%(n=1) had their creatinine clearance persistently below 15ml/min and 1%(n=1) inappropriately received once daily dosing of apixaban for 3 days. 19%(n=16) of all participants were on therapeutic LMWH. Treatment indications included acute coronary syndrome in 63%, suspected PE in 19%, newly diagnosed NVAF in 6% and bridging anti-coagulation while a DOAC is temporarily held in 13%. 6%(n=1) were inappropriately prescribed an under-dose. Conclusion Overall, there was an error rate of 16%(n=11) in DOAC prescriptions and 6%(n=1) in LMWH prescriptions. To address this, we propose an educational intervention for prescribers and the introduction of e-prescriptions with built-in alerts for errors. We plan to re-audit once these recommendations are implemented.