Factors influencing oral anticoagulant use in patients newly diagnosed with atrial fibrillation

Abstract

Background: We investigated factors that influenced oral anticoagulant (OAC) initiation and choice in Australian general practice patients newly diagnosed with AF. Methods: Using an Australian nationally representative general practice dataset, MedicineInsight, we identified patients newly diagnosed with AF between January 2009 and April 2019. Logistic regression analyses were used to examine factors associated with OAC initiation and choice. Results: A total of 63 212 patients with AF (53.7% males, mean age 72.4 years) were identified. Nearly two-thirds of these patients (40 854 [64.6%]) were initiated on an OAC, at a median time of 6 days after the documented diagnosis date. The proportion of patients who were initiated an OAC increased from 44.8% in 2009 to 72.2% in 2019 (P < .001). High risk of stroke (CHA 2 DS 2 -VASc, adjusted odds ratio (AOR), 4.39 [95% CI, 3.99-4.83]), low risk of bleeding (ORBIT, AOR, 1.87 [95% CI, 1.72-2.03]), not having a recorded history of dementia (AOR, 1.81 [95% CI, 1.65-1.98]) and male sex (AOR, 1.29 [95% CI, 1.22-1.35]) were independently associated with OAC initiation. Direct-acting oral anticoagulant (DOAC) use increased from 11.9% in 2011 to 94.0% of all OAC initiations in April 2019 (P < .001). Conclusions: The proportion of newly diagnosed patients with AF initiated on OAC increased markedly following the introduction of the DOACs. Of those initiated, 9 in 10 were receiving a DOAC at the end of the study period. There is potential underuse in women and individuals with dementia. K E Y W O R D S atrial fibrillation, oral anticoagulant, oral anticoagulant choice, oral anticoagulant initiation, primary care How to cite this article: Bezabhe WM, Bereznicki LR, Radford J, et al. Factors influencing oral anticoagulant use in patients newly diagnosed with atrial fibrillation.

Stroke risk reassessment and oral anticoagulant initiation in primary care patients with atrial fibrillation: A ten‐year follow‐up

“…Possible reasons for not prescribing an OAC in patients with high stroke risk, including high bleeding risk, frailty, use of antiplatelet agents, and dementia, are found elsewhere 29,30 . In our recent study using the MedicineInsight data set, we found that high risk of bleeding, having a recorded history of dementia or liver disease and female sex were independently associated with not being prescribed with an OAC 20 . A recent study by Steinberg et al found that almost one‐third of patients with high stroke risk and not prescribed an OAC had at least 1 major contraindication to OAC use; high bleeding risk was the most common contraindication.…”

“…29,30 In our recent study using the MedicineInsight data set, we found that high risk of bleeding, having a recorded history of dementia or liver disease and female sex were independently associated with not being prescribed with an OAC. 20 A recent study by Steinberg et al found that almost one-third of patients with high stroke risk and not prescribed an OAC had at least 1 major contraindication to OAC use; high bleeding risk was the most common contraindication. However, the use of an OAC in these patients was associated with lower rates of all-cause stroke, hospitalisation and mortality but with a higher risk of intracranial haemorrhage.…”

“…Details about this dataset can be found elsewhere. [17][18][19][20][21][22][23][24] Patients newly diagnosed with AF from 1 January 2007 to 31 December 2008 ('screening period') and aged 18 years or more were included in this study. Baseline CHA 2 DS 2 -VA scores were calculated by assessing documented comorbidities until 31 December 2008.…”

“…A total of 400 practice sites contributed data for this study. Details about this dataset can be found elsewhere 17‐24 . Patients newly diagnosed with AF from 1 January 2007 to 31 December 2008 (‘screening period’) and aged 18 years or more were included in this study.…”

Ten‐year trends in prescribing of antiarrhythmic drugs in Australian primary care patients with atrial fibrillation

“…It is the largest de‐identified Australian general practice database available to researchers. Details about the MedicineInsight dataset are available elsewhere 6–9 . Patients aged 18 years or older with at least three visits to their general practice in the previous 2 years and a recorded diagnosis of AF before the census time were included.…”