PO-04-217 IMPACT OF ELECTRONIC HEALTH RECORD BASED CLINICAL DECISION SUPPORT ON OFF-LABEL DOSING OF DIRECT ORAL ANTICOAGULANTS: RESULTS OF A SINGLE-CENTRE QUASI-EXPERIMENTAL STUDY

Abstract

Complex dosing regimens of direct oral anticoagulants (DOACs) increase the susceptibility to off-label dosing and use, leading to adverse safety profile. Electronic health record (EHR) clinical decision support (CDS) systems can facilitate medication prescription process and implement dosing guidance to providers. In this study we sought to evaluate the ability of EHR-CDS to reduce off-label dosing for DOACs across multiple indications. This is a retrospective single-center, quasi-experimental study from 2011 to 2021 to compare off-label DOAC dosing before and after implementation of EHR-CDS in 2018. Subgroup univariable and multivariable Logistic Regression analyses were conducted to compare off-label dosing of DOAC before and after EHR-CDS intervention across different indication of DOAC (AF, VTE treatment, VTE prophylaxis), DOAC types (apixaban vs rivaroxaban), and encounter type (inpatient, outpatient, and emergency visits) and CHA2DS2-VASC score (<2 vs ≥ 2). Overall, 16,521 patients (Mean age=67.8 ± 14.5, 43.7% Female) with DOAC prescription were included, of which 66.1%, 30.3%, and 3.6% received DOAC for AF, VTE treatment, and VTE prophylaxis, respectively. EHR-CDS was associated with reduced off-label dosing of DOACs for all indications (Pre EHR-CDS: 21.8% vs After EHR-CDS: 20.2%, P=0.03, OR:0.90(95%CI: 0.84-0.98)). When stratified by indication of DOAC prescription, type of DOAC and encounter type; this decrease was significant for VTE prophylaxis, (Pre EHR-CDS: 9.7% vs After EHR-CDS: 2.7%, P<0.001; OR: 0.25(0.12-0.57)), patients with rivaroxaban prescription (Pre EHR-CDS: 16.8% vs After EHR-CDS: 14.5%, P<0.001; OR: 0.84(0.74-0.95)), CHA2DS2-VASC score ≥ 2 (Pre EHR-CDS: 26.7% vs After EHR-CDS: 24.7%, P<0.001; OR: 0.90(0.83-0.98)) and outpatient settings (Pre EHR-CDS:23% vs After EHR-CDS:20.6% , P<0.001; OR:0.87(0.79-0.95)). The results of subgroup analysis were consistent after adjusting for demographics, and comorbidities (Figure). The present study demonstrates the EHR-CDS didn’t decrease off-label dosing for AF and VTE treatment indications, however, it decreased off-label dosing of DOACs, for VTE prophylaxis of patients undergoing hip or knee replacement surgery, patients with Rivaroxaban prescription, CHA2DS2-VASC score ≥ 2 and those in outpatient settings. Future studies are warranted to assess key barriers for successful implementation of EHR clinical decision support for decreasing DOACs off-label dosing in these settings.