Appropriateness of prescription of oral anticoagulant therapy in acutely hospitalized older people with atrial fibrillation. Secondary analysis of the SIM-AF cluster randomized clinical trial

Aims To assess the appropriateness of oral anticoagulant (OAC) prescription and its associated factors in acutely hospitalized elderly patients. Methods Data were obtained from the prospective phase of SIM-AF (SIMulation-based technologies to improve the appropriate use of oral anticoagulants in hospitalized elderly patients with Atrial Fibrillation) randomized controlled trial, aimed to test whether an educational intervention improved OAC prescription, compared to current clinical practice, in internal medicine wards. In this secondary analysis, appropriateness of OAC prescription was assessed at hospital admission and discharge. Results For 246 patients, no significant differences were found between arms (odds ratio 1.38, 95% confidence interval [CI] 0.84-2.28) in terms of appropriateness of OAC prescription. Globally, 92 patients (37.4%, 95% CI = 31.6-43.6%) were inappropriately prescribed or not prescribed at hospital discharge. Among 51 patients inappropriately prescribed, 82% showed errors on dosage, being mainly under-dosed (n = 29, 56.9%), and among 41 inappropriately not prescribed, 98% were taking an antiplatelet drug. Factors independently associated with a lower probability of appropriateness at discharge were those related to a higher risk of bleeding (older age, higher levels of aspartate aminotransferase, history of falls, alcohol consumption) and antiplatelet prescription at admission. The prescription of OACs at admission was the strongest predictor of appropriateness at discharge (odds ratio = 7.43, 95% CI = 4.04-13.73). Conclusions A high proportion of hospitalized older patients with AF remains inappropriately prescribed or nonprescribed with OACs. The management of these patients at hospital admission is the strongest predictor of prescription appropriateness at discharge.