Table 4.

Five key PRES domains [17, 18] with additions (bold) from synthesis of included studies results

Domains	Dimensions of domains	Examples provided	Authors’ recommendations
Relationship with research staff	Extent to which content and character of interactions with research staff meet or exceed participant expectations	Friendliness Professionalism Knowledge Approachability Helpfulness Respectfulness Responsiveness “Informativeness” “Appreciativeness”	Staff have appropriate training (support) and sufficient time to build relationships
Quality and timeliness of information	Range of formats and media	Accessibility and breath of formats to suit needs and expectations, e.g. written, verbal, video, online, SMS	Ensure the right information is available in the right place at the right time as participants proceed through the study
	Content, accuracy and comprehensiveness	Pre-consent information (Participant information sheet (PIS)) General information about the health condition ‘Practical’ process information, e.g. appointments, what to expect, where to be, when and how Updates and progress of the study Personal information, e.g. test results Overall study results
	Responsiveness	Responsive to questions
Engagement with diverse participant motivations	Extent to which study design/delivery satisfies a range of differing motivations for participation: ▪Altruistic ▪Health related ▪Opportunity for (relatively) flexible treatment options ▪Opportunity to relinquish personal responsibility for unforeseen effects whilst trying new treatment ▪Material incentives designed in by researchers	Altruistic Wanting to help others Health related Improved monitoring and care of own condition Hope of improvement in personal medical condition Improved understanding of personal condition Opportunity for (relatively) flexible treatment options Join randomised controlled trial (RCT) with a chance of receiving trial intervention, always with the freedom to withdraw (and potentially seek treatment off study) Join RCT and be randomised to non-intervention, but still have the opportunity for intervention later Opportunity to relinquish personal responsibility for unforeseen effects whilst trying new treatment RCT – willingly surrender to random allocation of treatment Material incentives designed in by researchers Thank you materials Condition specific equipment/servicing of equipment	Actively appreciate participants motivations
Study organisation	Extent to which study and intervention design/delivery accommodates participants’ time, monetary and physical/emotional costs	Appointment scheduling—frequency, length of time, flexibility Waiting times in clinic/between clinics Assessment burden/discomfort/distress Monetary expenses and how/when incurred/reimbursed Access including location proximity/convenience (any flexibility), travel and parking costs/time/burden Access for those with disabilities (visual impairment, wheelchair access, etc.) Unpleasant side effects or implications of intervention Lifestyle adaptions to accommodate intervention	Involve patients and the public in the earliest stages of the study and intervention design, to identify and mitigate factors which may contribute to adverse participant experiences ‘Walk-throughs’ to carefully consider participants’ pathway from pre-consent, through all study visits
Study environment	Extent to which research environments meet participants’ preferences and expectations	Noise levels Ambience (calm/busy) Attitudes of others (non-research related) in the environment Availability of refreshments	Carefully consider the effects of the environment participants will be moving through