RCT Concerning the Intention to Prescribe/Take Oral Anticoagulants for Atrial Fibrillation Depending on the Number of Risk Diagrams (w Treatment +/- w/Out Treatment), and Number of Years (1 or 5) for the Estimation of the Risk of Stroke.

Objectives:

To answer the questions:

1. Concerning the decision to prescribe (take) treatment on the basis of a decision aid, are there necessary both diagrams (that with risk without treatment, and that with risk under treatment), or it is enough only the second (risk under treatment, which normally gives all the needed information)?
2. Concerning the decision to prescribe (take) treatment, is it a difference between the effects of the presentation on decision aid of the risk of stroke for the next 1 year, and the presentation of the estimated risk of stroke for the next 5 years?
3. Is the decision different if physicians prescribe the anticoagulant treatment to patients, over if they should take it themselves?

Study: 2x3 factorial randomized controlled trial (RCT) for comparison:

1. Between the decision aid with 2 images (without treatment + with treatment) and the one with 1 image (risk only with treatment)
2. Between the effect of the presentation of the stroke risk chart for 1 year and the stroke risk chart for 5 years.
3. The decision to prescribe to patients over the decision to take the treatment themselves.