Table 2.

Co-development process based on coulter's framework for decision aid development.

Coulter's Framework for Decision Aid Development (12)	Methods
Scoping	The specific decision was defined based on the latest guidance for people with Lynch syndrome, informed by the clinical stakeholders specialising in Lynch syndrome management (EC, NR).
	The need for support in making this decision was recognised by the public involvement contributors with Lynch syndrome.
	A behavioural analysis of the six decision aids identified for people with a genetic predisposition to cancer via a systematic review (10) confirmed that none of these met all the IPDAS, supporting the need for a template for this population.
Steering Group	A patient panel including 12 patient contributors, and a stakeholder group including clinicians and low literacy decision aid experts were set up at the project outset (see Section 2.2)
Design 1 and 2: Assess Decisional Needs	Consultations were conducted with 19 people with Lynch syndrome via online discussion groups or telephone, co-facilitated by members of the patient panel. Discussions explored perceptions about managing cancer risk, and feedback on components from existing patient support resources* to identify the type of support people wanted.
	Discussions with the patient panel about how the decision aid could best engage its target audience informed the development of guiding principles [an intervention planning tool from the Person-Based Approach to promote engagement with interventions (23)].
	Relevant literature was signposted by clinician and decision aid stakeholders.
Design 3: Determine Format and Distribution Plan	Examples of existing decision aids* were reviewed with the patient panel to identify which components were useful, and important considerations in how these should be designed.
	Planned decision aid components were mapped back to the IPDAS and Ottawa Decision Support Framework to ensure key components had not been omitted.
	A programme theory was developed to show how the decision aid was hypothesised to improve decisional outcomes (19).
	Ongoing discussions with clinical stakeholders and patient panel about how these resources can best be implemented in mainstream care.
Design 4: Review and Synthesise Evidence	Guidance from clinical stakeholders regarding the latest evidence and guidelines around healthcare options.
Prototype Development	Detailed small group discussions about three iterative versions of decision aid with patient panel.
	Detailed written feedback from the patient panel on each version of the decision aid was also incorporated.
	Detailed written feedback on the decision aid content from clinical and decision aid literacy stakeholders (EC, NR, SS, PM).
	All feedback was collated in a table of changes (tool from the person-based approach) to help identify where changes were needed to improve the accessibility, relevance and usefulness of the decision aid.
Alpha Testing	Alpha and beta testing will be undertaken with clinicians and people from the target population, including think-aloud interviews, but is not reported in this paper.
Beta Testing

^*The existing patient support resources were selected to provide examples of a range of the core components of decision aids, defined as: “At a minimum decision aids describe the health condition or problem; make explicit the decision; provide information on options, benefits, and harms; and help patients clarify which benefits and harms matter most. Optional features in decision aids are probabilities of outcomes of options, narratives describing patients’ experiences with making decisions, and guidance in the process of decision making” (24).