The Encounter Decision Aid (EDA) is an interactive website designed for use by a participant and their clinician together. Together, the clinician and participant can go through the website together and input the participant's health information into the same stroke risk calculator also in the PDA. The EDA also provides information about the diagnosis of AF, living with this diagnosis, and possible treatments, and prompts discussion of how a participant's values affects these aspects of AF.

Preparation for Decision Making Scale is a validated scale which will assess participants' perspectives of the tools' usefulness in preparing them to communicate with their clinicians and for Shared Decision Making. These questions are answered on a Likert scale ranging from 1=not at all to 5=a great deal. A higher score indicates that they are better prepared and, thus, a better outcome.

The Quality of Communication survey is a 3-item modified version of the CAHPS Clinician and Group survey to determine the extent to which communication is patient-centered, contains technical information that is easily understood, and is respectful. Each item is assessed on a 3-point scale that will be individually reported: 1=Yes, definitely; 2=Yes, somewhat; and 3=No. The more 1's that are chosen indicates the higher quality of communication and, thus, a better outcome.

The SDMQ9 assesses the quality of participant involvement in the process of decision-making with their clinician from the perspective of the participant. Each item is assessed on a 6-point Likert scale from "completely disagree" to "completely agree". Clarity and knowledge would be indicated by "completely agree", so a higher score is "better".

This scale assesses participants' desire to participate in Shared Decision Making. This scale is an adaptation of the Degner & Sloan's Control Preference Scale. It is a one item question that asks people if they want to make the decision alone, with their clinician, or have their clinician make it. There is no right or wrong answer; it is up to patient preference, so no answer indicates a "better" than another.

This will be assessed with 5 questions. Participants will be asked questions about if they used the PDA before their appointment, used the PDA during their appointment, their likelihood to recommend the PDA, the amount of information presented, and if the PDA seemed biased. There is no "better" or more correct answer; it is up to the patient's opinion.

Collaborative agreement will assess decision concordance between the participant and the clinician. Both the participant and clinician will be asked to report about what decision (anticoagulation no/yes-which one) was made during the index visit. Decisions will also be abstracted from Electronic Health Records and through assessment of audiovisual recordings by research staff. Agreement will be calculated between all four sources and reported. There is no "better" score besides how many answers line up between the clinician and the patient; we are measuring understanding between them.

Anticoagulation Adherence 1 will be assessed by a 100-point visual analogue scale (VAS) where participants indicate the percentage of medication taken since prior visit. This ranges from 0% (did not take any of their medication as prescribed) to 100% (took all of their medication as prescribed). A "better" score would be indicated on how close to 100%, as the patient should be taking the medication as prescribed by their clinician.

A self-reported 7-day recall of pill-taking behavior. This asks participants whether they forgot to take any of their doses of medication (as prescribed). If they answer yes, they indicate the number of tablets missed per day, per week, and/or per month. Then they are asked how many pills they skipped in the past 7 days. They are asked how many days in the past week that they took more than the prescribed dosage of drug. The are asked if they had any side effects from their drugs, and if yes, what those side effects were. They are asked if they missed any doses due to the side effects. They are asked if the cost of their medication affected taking it. Finally, they are asked how taking their medication has changed their life.

For participants who choose to stay on Warfarin, we will also use as a measure of adherence: the proportion of international normalized ration (INR) tests obtained/scheduled. This includes 2 questions: was the patient on Warfarin prior to enrollment, and were INR measures taken after enrollment.

For participants who choose to stay on Warfarin, we will also use as a measure of adherence Time in Therapeutic Range. This is the duration of time in which the patients International Normalized Ratio (INR) is in the target range, typically values between 2 - 3. (INR is a blood test administered by the clinician to determine the patient's anticoagulation control.)

Treatment Choice will be assessed by asking participants to identify which treatment (drug) they chose and if their decisions would be different if there were no out-of-pocket costs.

Fidelity of SDM Tool by the clinician will be assessed by a review of the recording looking for key items to be addressed. A checklist of key elements will be assessed in all four arms to assess not only the fidelity but potential contamination. A sum of the components in the checklist will be calculated for each recording and compared across arms. There is no "better" score; we are measuring how they use the Decision Aid.

Strokes and bleeds requiring medical assistance will be monitored. Because very few of these are expected, we will rely on participant/clinician self-report and medical record review 12 months post enrollment for each participant. Chart review will include identification of clinical event outcomes: death, stroke, systemic embolism, transient ischemic attack clinically-relevant non-major bleeding, and major bleeding.

Encounter Length will be assessed by comparing the length in minutes of the discussion about anticoagulation and of the office visit between the different arms, when available. Study notes and video/audio records will be used to assess encounter length.

1-item instrument that determines if patients have minimizer or maximizer tendencies. Medical minimizers are individuals who prefer to do as little as possible when it comes to medicine and their health, whereas medical maximizers prefer active and aggressive medical treatments and being proactive about their health. There is no "better" score; it is up to patient opinion.

Anticoagulation persistence: Using data from pharmacy refills, we will calculate anticoagulation persistence throughout enrollment using the percent days covered (PDC) based on prescription refill behaviors (total days supply of anticoagulant filled / total days of observation from the first prescription fill date; range 0-100%). We will also pull all pharmacy refills for the 12 months prior to enrollment. This will allow us to calculate persistence for prior use of anticoagulants for the review cohort to compare to persistence post encounter and see if there is an impact.

Medical history relevant to study aims will be collected will be physiological parameters: such as hypertension, congestive heart failure, rheumatic heart disease, prior heart valve replacement, implantable cardiac device, deep vein thrombosis/pulmonary embolism, prior cerebrovascular events, diabetes mellitus, chronic renal disease, liver disease, coronary artery disease, peripheral arterial disease, prior major bleeding or predisposition to bleeding, medication usage predisposing to bleeding, alcohol use, medication prescribed during enrollment visit, concomitant medications, prior use of systematic anticoagulation for any reason, and INR measures (if the patient was on Warfarin previously, if INR measures were taken after enrollment).

This will be collected using a modified version of the Illness Intrusiveness Ratings Scale, a 13-item self-report instrument. The AIIR assesses the extent to which disease and treatment interfere with meaningful daily living among people affected by chronic disease. Answers range from 1=Not very much to 7=very much. A lower score is "better" because it would indicate that their daily life is not bothered very much by their choice of treatment.

1-item instrument that assesses patient preference of either taking a stroke prevention drug every day, which has a risk of causing serious bleeding, or not taking a stroke prevention drug every day, even though stroke risk is higher. There is no "better" answer; it is up to patient opinion.

This will be assessed with 6 questions answered by a 5-point Likert scale questioning satisfaction with discussion about anticoagulation medication choice. Answers range from 1=not at all satisfied to 5=completely satisfied. The clinician will also be asked whether they would recommend the approach used to other clinicians for other discussions on with a "yes/no/not sure" answer format. A lower score would indicate higher satisfaction, so lower is "better".

We will review the electronic medical record (EMR), patient- and clinician-reported choice, and recordings of the visit to determine the prescribed anticoagulant and whether and when switches to another agent or to no anticoagulant took place. Together, they should capture choice and switches even when these occur as a result of changes in clinician (e.g., from cardiology to primary care). When available, we will note the documented reasons from clinical notes for choosing and switching as well as with which clinician the change was made (e.g primary, cardiology, etc.).

1-item instrument that assesses patient self-reported health on a scale from 1 = "poor" to 5 = "excellent", which predicts mortality, hospitalization, and high outpatient use.