Electronic Supplementary Material 3 Summarises the Educational Component of the Computerised

Preferences for oral anticoagulants in atrial fibrillation: a best-best discrete choice experiment PharmacoEconomics Peter Ghijben, Emily Lancsar, Silva Zavarsek Centre for Health Economics, Monash University, Clayton 3800, Victoria, Australia Peter Ghijben Research Fellow

Centre for Health Economics, Monash University, Clayton 3800, Victoria, Australia Emily Lancsar Associate Professor

Centre for Health Economics, Monash University, Clayton 3800, Victoria, Australia Silva Zavarsek Senior Research Fellow Correspondence to: Peter Ghijben [email protected]

Electronic supplementary material 3 summarises the educational component of the computerised (video-based) survey used in the study. The figures presented capture a series of moments throughout the video-based survey and the text underneath provides the complete information provided to participants throughout the videos. “Hello and welcome, today I will be leading you through this survey. You will be presented with 16 hypothetical scenarios, and you will be asked to make choices between treatment options in each.

But first, to prepare you to answer those questions, you will learn about a heart condition which increases the chance of having a stroke, how stroke affects health, and the benefits and risks of different treatment options.

Please consider the information presented carefully and answer the questions “as if” this scenario was happening to you in “real life”. You can stop and re-play any of the information.

Let’s get started.

Imagine during a routine check-up, your local doctor detects an irregular heartbeat and refers you to a nearby heart specialist. You arrive at the heart clinic and the receptionist asks you to complete the following questionnaire prior to seeing the specialist.

Press next and please answer the questions.”

“Thanks for that. Now suppose the specialist is ready to see you.

After an examination, imagine the specialist diagnoses you with a condition called atrial fibrillation which is a type of irregular heart-beat associated with a high risk of stroke.

The specialist provides you with additional information about atrial fibrillation, stroke and the possible treatments to prevent stroke.

Please consider the following information carefully.”

“ Atrial fibrillation is a very common heart condition where the heart beats irregularly and often quickly.

The condition prevents blood from flowing properly through the heart which means blood-clots can form. Blood clots are lumps of solid blood and can travel to the brain and cause a stroke.”

“Stroke involves a loss of brain function due to insufficient blood reaching the brain.

Strokes can be minor or major in severity and there is no way of knowing which type will occur. There is a 50:50 chance a stroke will be minor or major.”

“A ‘typical’ minor stroke can be described by the following scenario: • You suddenly cannot move or feel your arm and leg on one side • You have mild difficulty saying what you want to say but • There is no physical pain • You are admitted to hospital and • You return home after one week • Your weakness and numbness improve, but slight weakness and numbness of your arm and leg remains • You regain normal speech and • You have normal function for most everyday activities • You have an increased risk of having more strokes but • The risk can be decreased with medications • People rarely die from a minor stroke”

“A ‘typical’ major stroke can be described by the following scenario: • You suddenly feel dizzy and you are unable to move or feel your arm and leg on one side of your body • You cannot swallow, your speech is slurred and it is difficult for others to understand you • You are unable to say what you want to say and you are unable to understand what is being said to you • There is no physical pain • You are admitted to hospital and stay for several weeks • About 1 in 5 people will die within weeks of their major stroke • After leaving hospital and for the rest of your life you require help to walk, you have difficulty thinking clearly, your speech remains slurred and difficult to understand, you have difficulty understanding what others are saying except for simple instructions, you are able to dress and feed yourself but you have poor bladder and bowel control • You may need to live in a nursing home and another stroke or illness such as pneumonia is likely to cause your death sometime over the next several years” “Overall, the chance of dying from a stroke is 12%.”

“Medications to ‘thin the blood’ can be used to stop blood-clots forming and lower the risk of stroke occurring.

However because they ‘thin the blood’, unfortunately, these medications may also increase the risk of bleeding events, such as internal bleeding.

Because bleeding is a possible side-effect of ‘blood-thinning’ medications, when using them it is important: i) To take extra steps to avoid getting hurt ii) To always tell any doctors and dentists about the medication, and iii) To carry an “Alert Card” in your wallet to warn paramedics” “Bleeding can occur anywhere in the body, including the brain

All bleeding is serious and requires treatment, but the severity can vary, with about half considered to be ‘life-threatening’.

The most common type of bleeding occurs in the stomach and may typically be described by the following scenario: • You feel unwell for two days then suddenly vomit blood • You are admitted to hospital • A doctor puts a tube down your throat to see where you are bleeding and • You receive sedation to ease the discomfort of the test • No operation is needed but • You receive blood transfusions to replace the blood you lost • Your hospital stay is for 2 - 7 days and • You are tired for 3 weeks before you recover • You are prescribed more medication to be taken for the next 2 – 6 weeks to prevent further bleeding, and • You may have to discuss the need for a change in medication with your doctor • After that you are back to normal

More serious bleeds however can have long-term effects on your health, including brain and organ damage.

Overall, the chance of dying from bleeding is 8%.” “Some, but not all, ‘blood-thinning’ medications have antidotes to immediately reverse their blood-thinning effect, so if a severe bleeding event does occur, the antidote can be used to reduce the duration and severity of the bleeding event.”

“Some, but not all, ‘blood-thinning’ medications need a blood test once a month (on average) to make sure they are working effectively and safely.

Typically, the blood test involves attending a local medical clinic where a small sample of blood is drawn from your arm and sent to a laboratory for analysis. You must then call the clinic within 24 hours for the results and follow any instructions provided (such as a change in the dose of your blood-thinning medication).” “Blood-thinning medication tablets are taken either once or twice a day and treatment is often continued for life.”

“Some, but not all, ‘blood-thinners’ have the potential to interact with other medications, food and even some illnesses.

Interactions may stop medications from working properly and may even cause additional unwanted side-effects (such as bruising).

To limit potential interactions from happening, all doctors, dentists and pharmacists should be informed about the ‘blood-thinner’ before starting any new medications. Maintaining a well-balanced and consistent diet is also important.” “Depending on which ‘blood-thinning’ tablet is prescribed, the price you pay at the pharmacy each month may be different.”

“To summarise:

Atrial fibrillation is a heart condition that increases your risk of having a stroke.

If a stroke occurs, there is a 50:50 chance it will be minor or major in severity and the overall risk of dying from stroke is 12%.

The long-term problems of minor stroke include mild weakness in an arm and a leg on one side of your body, but you have no problems with thinking and speaking and you remain independent in everyday activities. The long term problems of major stroke include severe weakness in an arm and leg on one side, difficulty understanding what others are saying, and you are dependent on others for everyday activities.

‘Blood-thinners’ are medicines used to lower the risk of stroke by ‘thinning’ the blood. Unfortunately because they ‘thin’ the blood, bleeding is a possible side effect.

Bleeding can occur anywhere in the body including the brain. All bleeding requires treatment and about half are considered ‘life-threatening’. The most common place of bleeding is in the stomach from which people usually recover; however more serious bleeds can cause long-term problems such as organ damage. Overall, the risk of dying from bleeding is 8%.

These medications also may require blood tests every month, they may be have the potential to interact with other drugs or food, they may have an ‘antidote’ to treat bleeding if it occurs, and they may cost you money each month.”

“Now before we move on, we are going to briefly talk about probability and risk.” “Imagine there is a 4% risk of having a stroke in any year. This means out of 100 people, without medication, 4 will have a stroke and the other 96 people will not.

The same information is presented using 100 faces in the picture above, where each face represents one person.”

“The faces shaded blue represent those 4 out of the 100 people who do have a stroke; the 96 faces shaded white represent those who do not have a stroke.” “Now imagine that by taking a blood-thinning medication, those 100 people can reduce their risk of having a stroke by 80%.

This means that of the 4 people who would have had a stroke without the medication, now by taking the medication: - about 3.2 people will be ‘prevented’ from having a stroke, but - about 0.8 people will still have a stroke”

“The number of faces shaded blue in the picture has reduced from 4 to 0.8, because on average only 0.8 out of the 100 people will have a stroke when taking the medication.” “Okay. Now imagine the specialist tells you that your risk of having a stroke because of the heart condition is 4% per year (or 4 out of 100) and that your risk of having a bleeding event is 2% per year (or 2 out of 100);

These represent your current risks without taking any medication, and are shown in the picture below.

Remember these are hypothetical made-up risks but we want you to imagine “as if” they apply to you.” “ Imagine the specialist wishes to discuss the different ‘blood-thinning’ medications available to lower your risk of suffering from a stroke. The specialist is interested in your opinion and wants to know which treatment option you would choose. To help you decide, the specialist presents you with a number of “choice-sets” that include different treatment options.

An example choice-set is shown below.

There will always be 3 treatment options presented in each choice-set.

The 3 treatment options will always be labelled as “No treatment”, “Drug A” and “Drug B” at the top of the page.

The 3 options will always be described using the same 7 characteristics you learnt about earlier and these will always be displayed along the far left side of the page. These characteristics include 1. The risk of stroke 2. The risk of bleed 3. Whether an ‘antidote’ is available to treat bleeding 4. Whether a monthly blood test is required 5. The dose frequency, or the number of times a day the tablet must be taken 6. Whether drug interactions are likely, and 7. The cost to you per month

Each treatment option will always include these characteristics, but how these characteristics are described will vary across the 3 options. For example, the first option from the left is labelled “No treatment”. This option describes your current risk of stroke and risk of bleeding that you were told about earlier. Because this option does not involve taking medication, the other characteristics (such as ‘monthly blood test’) are not relevant. The description of “No treatment” will be the same for the rest of the survey.

The other 2 options labelled “Drug A” and “Drug B” are shown next to the “No treatment” option and represent different ‘blood-thinning’ medications. These options describe the risk of stroke and the risk of bleeding that you would face when taking these medications, and the other characteristics associated with their use. The descriptions of “Drug A” and “Drug B” will change throughout the survey because they involve taking different medications.

Now imagine the specialist asks you to compare the 3 treatment options and indicate which option you would choose by selecting the box under that option. Then you will be asked from the remaining 2 options which you would choose.

To get you started, here is a practice question.” “Great, now let’s get started with the main survey questions. You will now be presented with 16 different choice-sets.

Remember to indicate which option you would choose.”