Table 1.

Attributes and levels in the DCE

Attribute	Definition	Levels
Mode and frequency of administration	Not all anaemia treatments are given/taken in the same way; for example, some are pills and others are injections Oral pill: A tablet would be taken once per day, but the number of days per week that they are taken varies between treatments Injection under the skin (SC injection): This requires a short needle to be injected into a pinch of skin. Common areas (sites) to inject are the abdomen, arm and thigh. There may be some pain and/or bruising at the injection site after injecting • The injection would be delivered at home, either by an HCP, yourself, a friend or a family member • If you deliver the injection yourself, you will receive training from an HCP • You would need to store the injections in a refrigerator until they are used • The benefits and risks of a treatment are not related to the mode and frequency of administration	Oral pill, once daily, at home Oral pill, three times a week, at home SC injection, once every 2 weeks, at home (reference) SC injection, once every 4 weeks, at home
Need for iron supplements	Depending on the treatment that you take, you may also need to take additional iron supplements. This can either be in oral or IV form Oral iron pill: At least one tablet would be taken once per day, over a period of 3–6 months IV iron infusions: These require a needle to be inserted into a vein, often in the arm. This must be done by an HCP in a medical facility. The infusion will take between 30 min and 3 h. There may be some pain at the injection site owing to the IV infusion • The benefits and risks of a treatment are not related to the need for iron supplements	Intravenous iron once every 3–6 months, in a medical facility (reference) Oral iron daily, at home No iron supplements
Risk of gastrointestinal side effects	Some treatments increase the risk of experiencing gastrointestinal side effects. This risk depends on the treatment that you are taking • Gastrointestinal side effects may include nausea (feeling sick), vomiting (being sick), diarrhoea (loose stools), bloating (feeling full or tight in your abdomen) or constipation (difficulty passing stools). The side effects are not severe but may be unpleasant or uncomfortable to experience. The risk of gastrointestinal effects will last for as long as you are on the treatment	0%: 0 out of 100 people will experience gastrointestinal side effects 20%: 20 out of 100 people will experience gastrointestinal side effects 50%: 50 out of 100 people will experience gastrointestinal side effects (reference)
Risk of a major cardiovascular event	Some treatments increase the risk of a major cardiovascular event. This risk depends on the treatment being taking • Major cardiovascular events include stroke (interruption in the flow of blood to the brain), heart attack, hospitalisation for severe chest pain and heart failure (wherein the heart cannot pump blood throughout the body properly). All of these events would require hospitalisation at minimum, and at worst, they could be fatal. The risk of a major cardiovascular event will last for as long as you are on the treatment	5%: 5 out of 100 people will experience a cardiovascular event 10%: 10 out of 100 people will experience a cardiovascular event 15%: 15 out of 100 people will experience a cardiovascular event (reference)
Energy levels	• The main symptom of anaemia is tiredness. These treatments are meant to improve your anaemia-related tiredness and increase your energy levels. However, not all treatments will improve your energy levels in the same way. This attribute defines the frequency in which you will feel like you have a lot of energy once you are on the treatment	You always have a lot of energy You sometimes have a lot of energy You rarely have a lot of energy (reference)

DCE discrete choice experiment, HCP healthcare professional, IV intravenous, SC subcutaneous