TABLE 1.

Major design requirements derived from background research with patients and the public

Source	Issue	Requirements
Patient fora	Fear of poor prognosis	Address language, appearance and provide links to support
	Other tools provide different predictions	Guidance on interpreting prognostic statistics
	Averages not perceived as relevant to individuals	Guidance on interpreting prognostic statistics
	Predictions must be based on old data to provide long term predictions	Guidance on interpreting prognostic statistics. FAQ section.
	Treatment benefit sometimes perceived to be surprisingly small	Ability to trade‐off benefits and adverse effects
Public survey n = 50, mean age = 37, SD = 10	Appearance too basic and impersonal	Address language, appearance and provide links to support
	NHS critical to instilling trust	More prominence to NHS branding
	Want more information about side effects	Ability to trade‐off benefits and adverse effects
	Outputs difficult to read/interpret	Improved visualisation of results
	Averages not perceived as relevant to individuals	Guidance on interpreting prognostic stats
Public focus group n = 7, mean age = 46, SD = 13	Fear of poor prognosis	Address language, appearance and link to support
	Desire to take part in decision‐making	Facilitate communication between patients and clinicians
	Technical information important but incomprehensible	Rewrite technical information to improve comprehension
	Preference for abstract visualisations. Icons representing people too upsetting	Consider emotional impact in design of graphics and labelling
	Want information on side effects	Ability to trade‐off benefits and harms