Low Use of Oral Anticoagulant Prescribing for Secondary Stroke Prevention: Results From the Ontario Stroke Registry.

BACKGROUND

Oral anticoagulation reduces the risk of stroke in atrial fibrillation but is often underused.

OBJECTIVES

To identify factors associated with oral anticoagulant prescribing and adherence after stroke or transient ischemic attack (TIA).

RESEARCH DESIGN

Retrospective cohort study using linked Ontario Stroke Registry and prescription claims data.

SUBJECTS

Consecutive patients with atrial fibrillation and ischemic stroke/TIA admitted to 11 stroke centers in Ontario, Canada between 2003 and 2011.

MEASURES

We used modified Poisson regression models to determine predictors of anticoagulant prescribing and multiple logistic regression to determine predictors of 1-year adherence.

RESULTS

Of the 5781 patients in the study cohort, 4235 (73%) were prescribed oral anticoagulants at discharge. Older patients were less likely to receive anticoagulation [adjusted relative risk (aRR) for each additional year=0.997; 95% confidence interval (CI), 0.995-0.998], as were those with TIA compared with ischemic stroke (aRR=0.904; 95% CI, 0.865-0.945), prior gastrointestinal bleed (aRR=0.778; 95% CI, 0.693-0.873), dementia (aRR=0.912; 95% CI, 0.856-0.973), and those from a long-term care facility (aRR=0.810; 95% CI, 0.737-0.891). After limiting the sample to those without obvious contraindications to anticoagulation, age, dementia, and long-term care residence continued to be associated with lower prescription of oral anticoagulants. One-year adherence to therapy was similar across most patient groups.

CONCLUSIONS

Age, dementia, and long-term care residence are predictors of lower oral anticoagulant use for secondary stroke prevention and represent key target areas for quality improvement initiatives.