The quality of oral anticoagulation in general practice in patients with atrial fibrillation.

BACKGROUND: The aims of this study were to evaluate the quality of oral anticoagulation (OAC) in AF patients in the practices of general practitioners (GPs) in Germany and to investigate possible causal factors which influence OAC quality.

METHODS: We conducted a multi-center, non-interventional, prospective observational cohort study among general practitioners (GPs) in Germany. To assess the quality of OAC on the basis of the prospectively documented international normalized ratio (INR) values, the time in therapeutic range (TTR) was calculated using the Rosendaal linear trend method. The causes of poor OAC quality were identified by a multivariate analysis model (logistical regression; poor OAC quality: TTR <60%).

RESULTS AND CONCLUSIONS: For 525 OAC patients (66.8%; patients with at least 2 prospectively documented INR values) the average TTR (target range of 2.0-3.0) was 67.6%. About 34.7% of the patients had a TTR <60%. None of the variables representing characteristics of the medical practices were capable of explaining the occurrence of poor OAC quality. However, with regard to care provision-based variables, the existence of a brief discontinuation of medication was important. As the existence of adherence barriers increased, the probability of poor anticoagulation quality increased. In conclusion, the provision of OAC in the German health care system is to be regarded as good, but far from ideal. Our causal analysis shows that patient-based factors should be addressed through the provision of improved training and that the rationale behind the interruption of OAC treatment should be critically examined.