Drug Persistence/Adherence in Patients Treated With Dabigatran or VKA for Stroke Prevention in Non Valvular Atrial Fibrillation (SPAF)

4000 AF patients receiving Pradaxa or VKA for stroke prevention will be followed up for 12 months in quarterly visits. Prescriptions, adverse events and (if applicable) reasons for definitive treatment discontinuation will be collected. At 6 months, patient adherence will be assessed, using the Morisky Score.