Oral anticoagulation use by patients with atrial fibrillation in Germany

Abstract

Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder. Oral anticoagulation (OAC) is recommended by guidelines in the presence of a moderate to high risk of stroke. Based on an analysis of claims-based data, the aim of this contribution is to quantify the stroke-risk dependent OAC utilisation profile of German AF patients as well as the possible causes and the associated clinical outcomes of OAC under-use. Our data set was derived from two large mandatory German medical insurance funds. Risk stratification of patients was based on the CHADS2-score and the CHA2DS2-VASc-score. Two different scenarios were constructed to deal with factors potentially disfavouring OAC use. Causes of OAC under-use and its clinical consequences were analysed using multivariate analysis. Observation year was 2008. A total of 183,448 AF patients met the inclusion criteria. This represents an AF prevalence of 2.21%. The average CHADS2-score was 2.8 (CHA2DS2-VASc-score: 4.3). On between 40.5 and 48.7% of the observed patient-days, there was no antithrombotic protection by OAC, other anticoagulants or aspirin. Older female patients with a high number of comorbidities had a higher risk of OAC under-use. Patients who had already experienced a thromboembolic event had a lower risk of OAC under-use. In the observation year, 3,367 patients experienced a stroke (incidence rate 1.8%). In our multi-level Poisson random effects estimate, OAC use decreases the stroke rate by almost 80% (IRR 0.236). In conclusion, OAC under-use is widespread in the German market. It is associated with severe clinical consequences.

Factors Associated with Anticoagulation Delay Following New-Onset Atrial Fibrillation

“…The emergence of sex as an important factor in OAC use is consistent with multiple previous studies demonstrating that OAC tends to be underutilized in women with AF. 8,14 Our study extends prior observations by indicating that women also are started on OAC later than their male counterparts, with 73% of men being on OAC at 1 month versus only 70% of women. Although the reason for this disparity is not entirely clear, this gender gap may be an important target for improving care quality since women with AF are at greater stroke risk compared to their male counterparts.…”

“…Comorbidities prevalent at AF diagnosis were defined using the presence of at least 1 ICD-9 code for a given condition at any time prior to the index AF encounter in a manner similar to that used in previous studies. 8,11 Baseline medication use was defined as the presence of a medication prescription within 30 days prior to AF diagnosis. Reversible AF was defined as the concomitant presence of AF with an ICD-9 code diagnosis corresponding to cardiac surgery or thyroid disease.…”

“…5,6 Despite this recommendation, evidence repeatedly demonstrates that up to 50% of patients with an indication for OAC do not receive it. 7,8 Although previous studies have exposed clinical factors associated with a lower incidence of OAC such as female sex and older age, 8 to date studies have not focused on factors relating to a potential delay in initiation of OAC therapy after a new diagnosis of AF. Indeed, consideration of factors related to delayed OAC initiation may expose patient, provider, or other systemic characteristics that could be targeted to reduce the total time AF patients are exposed to elevated stroke risk through lack of thromboembolism prophylaxis.…”

Influence of novel oral anticoagulants on anticoagulation care management

“…As one respondent noted, 'Some patients that should have been treated with oral anticoagulants were not treated in the past because of the challenges of VKA therapy, but now they can be treated with NOACs.' Under-usage of oral anticoagulants in the pre-and early-NOAC era was also reported in other developed countries and availability of NOACs reduced the undertreated population (14,15). Similar observations were also recorded in our study, as data analysis revealed that the treated population increased from an average of 7.4 % per year to almost 55.000 in 2015 (Table I).…”

Using the CHADS₂ and CHA₂DS₂-VASc Scores for Stroke Risk Prediction as well as the Identification of Stroke Outcomes and Cardiac Complications in Patients with and without Atrial Fibrillation

“…However, numerous studies have shown that ‘high-risk' patients are often undertreated [7,8]. We are also getting better at handling warfarin with efforts to improve the quality of international normalized ratio control, as reflected by the average time within therapeutic range [9], as well as the availability of novel OAC that overcome the many limitations of warfarin [10,11].…”