AF is the most common cause of irregular heart rhythm, becoming more common with age. People with AF may not have any symptoms, but sometimes develop blood clots in the upper chambers of their heart, which may break off and lodge in the brain causing stroke. As a result people with AF are at much higher risk of stroke than others of similar age and sex. The chances of a person with AF having a stroke are greatly reduced if they take anticoagulant drugs, which reduce the tendency of blood to clot. It is therefore important that GPs identify people with AF and that they offer anticoagulant drugs to them to reduce their chances of developing strokes. At present it is believe that many patients with AF who could benefit from anticoagulant drugs are not prescribed them. One way to increase the number of persons with AF who are prescribed anticoagulants is for general practices to identify patients from their electronic patient records who have a diagnosis of AF, to invite them for a checkup and to offer treatment to those who attend. This differs from the usual way of doing things which is to offer patients with AF treatment when they attend their GP for another reason. One general practice in Birmingham is proposing a project to actively invite patients with AF for invitation and assessment. We will evaluate their project to see how many patients are invited, how many attend, how many are started on treatment and to assess their opinions on the experience of invitation and assessment. The aim is to see if this project could be extende to othe general practices.