Table 3 The COREQ checklist

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