Table 3.

The COREQ checklist

Item	Description
Domain 1: Research team and reflexivity
Interviewer	Researchers KB and KO will conduct the interviews
Credentials of interviewers	KB MSc Environmental Epidemiology and Policy
	KO MA English Literature
Occupation of interviewers	Researchers based in Department of Health Sciences, Seebohm Rowntree Building, University of York, Heslington, York YO10 5DD, UK
Gender of interviewers	Female
Training and experience	Researchers conducting interviews have undergone basic training in qualitative methods, and will be closely supervised and mentored by CCG/SG
Relationship with patients	Researchers may have conducted a baseline interview with patients prior to qualitative interview, or may not have met or spoken to the interview participant before
Participant knowledge of the interviewer	The research and purpose of the interview will be explained as part of the consent process with the participant
Interviewer characteristics	Interviewers conducting the qualitative study are members of the research team for the CASPER Plus study, thus potentially biased in their view of the intervention and trial
Domain 2: Study design
Theoretical framework	The qualitative exploration has some a priori assumptions; an initial thematic analysis using principles of constant comparison will be followed by analysis using the Normalisation Process Theory [42] in order to explore how the intervention might be incorporated into routine practice
Sampling of participants	A purposive sample of patient participants will be invited to be interviewed, ensuring variation in age (65 to 79 years and 80+ years), gender, research site. We invite patients who have completed the intervention and those who decline to participate in the trial and those who have ‘dropped out’
	All CMs will be invited to be interviewed
	All GPs in participating practices will be invited to be interviewed, and sampling will ensure a mix of age, years in practice, gender, demography and size of practice
Method of approach	Potential patient participants were invited by mail which included a letter, information leaflet and consent form
	CMs were approached either directly or by email with information leaflet and consent form
	GPs were contacted by email or letter, with attached information leaflet and consent form
Sample size	Sample size of CM data set will be limited by number of CMs in the trial
	Interviews with patient participants and GPs will continue until category saturation is achieved in each data set
Non-participation	We will record how many potential participants who were invited declined to participate
Setting	CMs and GPs will be interviewed in their place of work
	Patient participants will be offered a choice of venue for the interview: home visit, GP practice, university office, other venue of their choice
Presence of non-participants	For patient participants, it is possible that spouses or carers may be present during the interviews
Domain 3: Data collection
Interview guide	The interview guide will be developed by the research team with reference to their previous work, the wider literature and through discussion of the study’s aims and objectives
Repeat interviews	No repeat interviews are planned
Recording	Interviews will be audio-recorded, downloaded and transcribed (anonymising the data at this point). The digital recording will be deleted
Field notes	Field notes will be kept by the interviewers, and discussed in research meetings. These notes will contribute to modification of the interview guide and to data analysis
Duration	A record of the duration of each interview will be kept
Data saturation	Interviews will be conducted until data saturation is achieved in each data set
Transcripts returned	We do not plan to send the transcripts to participants for comment
Domain 4: Analysis and findings
Number of data coders	Three researchers (KO, KB, CCG) will conduct data coding, with discussion of the coding at regular research meetings
Description of the coding tree	We do not plan to publish a description of the coding tree
Derivation of themes	Some of the themes will be a priori themes, anticipated from the wider literature; we anticipate that new themes will emerge from analysis of the data, specific to this age group of patients
Software	Software will not be used to organise the data
Participant checking	We anticipate that there may be occasional instances when we need to re-contact the participant to clarify some point in the transcript
Reporting - Quotations	We will use illustrative data extracts to support our findings
Data consistency	We will look for dis-confirmatory evidence as we conduct interviews and analysis. We will result such evidence
Clarity of major themes	We will present the major themes in any publications
Clarity of minor themes	We will present minor themes and dis-confirmatory evidence in our outputs, particularly in report to HTA