An interrupted time series study of electronic health record clinical decision support for providers caring for patients with atrial fibrillation at increased stroke risk.

PURPOSE: To measure the effect of clinical decision support (CDS) on anticoagulation rates in patients with atrial fibrillation (AFib) or atrial flutter (AFlut) at high stroke risk and receiving care in outpatient settings, and to assess provider response to CDS. METHODS: This observational, quasi-experimental, interrupted time series study utilized electronic health record data at a large integrated delivery network in Texas from April to November 2020. CDS consisted of an electronic Best Practice Advisory (BPA)/alert (Epic Systems Corporation, Verona, WI) with links to 2 AFib order sets displayed to providers in outpatient settings caring for non-anticoagulated patients with AFib and elevated CHA2DS2VASc scores. Weekly outpatient anticoagulation rates were assessed in patients with high stroke risk before and after implementation of CDS. Alert actions and acknowledgment reasons were evaluated descriptively. RESULTS: Mean (SD) weekly counts of eligible patients were 8,917 (566) before and 8,881 (811) after implementation. Weekly anticoagulation rates increased during the pre-BPA study period (ß1 = 0.07%; SE, 0.02%; P = 0.0062); however, there were no significant changes in the level (ß2 = 0.60%; SE, 0.42%; P = 0.1651) or trend (ß3 = -0.01%; SE, 0.05%; P = 0.8256) of anticoagulation rates associated with CDS implementation. In encounters with the BPA/alert displayed (n = 17,654), acknowledgment reasons were provided in 4,473 (25.3%) of the encounters, with prescribers most commonly citing bleeding risk (n = 1,327, 7.5%) and fall risk (n = 855, 4.8%). CONCLUSION: There was a significant trend of increasing anticoagulation rates during the pre-BPA period, with no significant change in trend during the post-BPA period relative to the pre-BPA period.