Table 5.

Guiding principles for engaging target population in decision aid, co-developed with patient panel.

Intervention objective:
The aim of the decision aid template is to support people with a genetic predisposition to cancer to make informed, values-based decisions about managing their risk of cancer.
User characteristics:
•Wide range of users in terms of specific risks, cancer history, cancer experiences within the family, and length of time since diagnosis of genetic predisposition.
•Some people have lower health literacy and lower motivation to engage with risk management.
•People have experiences of their GP not knowing about management options for their genetic predisposition, limited support beyond first diagnosis, and confusion due to inconsistent information.
•Some people are quite anxious and don’t want to be frightened.
Design objectives to promote engagement	Key (distinctive) intervention features
Each objective should be targeted toward a particular behavioural issue	Features that will achieve the design objective, preferably features that make the intervention unique
Promote trust in the decision aid as a credible source of information	Seek endorsement from charities
	Emphasise that the decision aid was developed by people with genetic predispositions
	Help people feel reassured that this is clinically safe advice, use existing information from credible health services where appropriate.
	Transparency about what is not known, to increase trust. Explain where evidence is limited or may change.
	Include citations for evidence, in line with IPDAS and to show people the intervention is evidence-based.
Support people to feel positive about their risk management decisions and reduce anxiety and distress.	Explain at the outset that it is a personal decision with no right or wrong.
	Use of positive language that emphasises the benefits of knowing your risk and the effectiveness of risk management options
	Stories of people who used their values to help inform their decisions
	Do not expose people to frightening information unnecessarily, e.g.,
	•This gene alteration has the highest risk of bowel cancer.
	•Public involvement contributors prefer the term “chance” to “risk”
	Signpost to support and encourage people to seek professional support that they are entitled to, e.g., gynaecologist appt
	Position the decision aid from the start as something you might want to talk about with your healthcare professional.
Include broad coverage of all topics that people may be uncertain about, even where information is regionally different or not currently clear.	Clear information about all aspects of risk management for genetic predisposition, including those that are not recommended by local guidelines but that people may have read about elsewhere.
	Show options in table form with clear information about possible outcomes
	Use a consistent format across each decision for clarity
Ensure intervention feels personally relevant	Make it clear on the very first page who the decision aid is for and what it will do
	Allow users to choose which information they are interested in
	Tailor risk information to user's characteristics
	Include stories from a wide range of people
	Involve a wide range of public involvement contributors and participants in intervention development
	Carefully develop content to ensure it is as personally relevant as possible, working closely with public involvement contributors
Accessible for everyone, including those with low health literacy	Risk presented in user-friendly ways, informed by evidence and public involvement
	Present information using fuzzy trace theory to show the gist first, and more information if desired.
	Definitions of medical words if hover over
	Use short sentences and active voice
	Low reading age when run through readability checker
	Put table showing implications of each option at the start to ensure people can access this information without having to read through everything first.