title: Atrial fibrillation in New Zealand primary care: Prevalence, risk factors for stroke and the management of thromboembolic risk.
abstract: Background Atrial fibrillation is a major risk factor for stroke and heart disease but there is limited information on its prevalence in New Zealand primary care or the treatment provided to manage thromboembolic risk. Our aim was to estimate the prevalence of atrial fibrillation, assess patient risk for thromboembolism and evaluate the appropriateness of risk reduction using antiplatelet and oral anticoagulation therapy. Design A retrospective cohort study utilising electronic medical records for 739,000 patients registered with 170 general practices in 2014. Methods Patient diagnoses and prescriptions from 2010-2014 were analysed to identify patients with atrial fibrillation in 2014 and co-morbidities included in the CHA2DS2-VASc algorithm. Adjusted prevalence of atrial fibrillation by patient demographic group and the proportion of patients following recommended antithrombotic therapy were calculated. Results 12,712 patients were identified with AF (1.72%, 95% confidence interval 1.69%-1.75%). Prevalence was significantly higher for Maori (odds ratio 1.91, 95% confidence interval 1.80-2.03) than Europeans after adjusting for age, sex, deprivation and clinical risk factors. Stroke risk for Maori and Pacific Island patients was higher than for Europeans across all age groups. Of the 10,406 patients (81.9%) at high risk for thromboembolism, 60.5% were using anticoagulants, 24.1% aspirin monotherapy and 15.4% neither anticoagulants nor aspirin. Oral anticoagulants were used by 31.5% of patients at low risk (CHA2DS2-VASc <2). Conclusions Oral anticoagulants are under-utilised in the management of thromboembolic risk in high risk patients with atrial fibrillation. Better promotion of guideline recommendations for the treatment of patients with atrial fibrillation may be required to improve clinician and patient decision-making.
authors: 1 Best Practice Advocacy Centre New Zealand, Dunedin, New Zealand.
authors: Andrew M
authors: AM
authors: Tomlin
authors: 1 Best Practice Advocacy Centre New Zealand, Dunedin, New Zealand.|2 Department of General Practice and Rural Health, Dunedin School of Medicine, New Zealand.
authors: Hywel S
authors: HS
authors: Lloyd
authors: 1 Best Practice Advocacy Centre New Zealand, Dunedin, New Zealand.|2 Department of General Practice and Rural Health, Dunedin School of Medicine, New Zealand.
authors: Murray W
authors: MW
authors: Tilyard
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000208:ethnology; D015897:Comorbidity; D057286:Electronic Health Records; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D016017:Odds Ratio; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'; D015995:Prevalence; D011320:Primary Health Care; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000208:ethnology / Q000517:prevention & control*; D013923:Thromboembolism / Q000175:diagnosis / Q000208:ethnology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors
keywords: Atrial fibrillation; anticoagulants; healthcare disparities; primary health care; risk reduction; stroke