Questionnaire development
A review of available validated questionnaires did not identify a suitable tool; therefore, we devised a dedicated questionnaire for the purpose of this study (Table S1). This was developed in collaboration with the two patient co-investigators and addressed imaging-specific issues and also included factors around staff support that may affect acceptability of imaging within clinical trials (GRIPP2SF, Table S2). All study documentation, questionnaires, Patient Information Sheet (PIS), consent form and invitation letter were reviewed by The Royal Marsden Patient and Carer Research Review Panel. The questionnaire development was an iterative process, involving input from a Radiologist, Research Radiographers, trial staff and patient representatives that led to a final version consisting of nine questions covering: 1) Scan parameters, including type of scan, scan preparation, scan procedure and perceived risks 2) scan scheduling, including duration and frequency 3) study participation discussion with a member of the study staff about the imaging procedures, the need for scanning and the research study and 4) external factors that could influence participation e.g. caring responsibilities, travel, costs etc. The content was based on experience of previous patient questionnaires and led by patient consultation. Testing was performed within The Royal Marsden by patient groups, radiographic and trial coordination staff. The questionnaire was individualised for the three groups.
The final versions of the questionnaire were approved by the Patient and Carer Research Review Panel at the Royal Marsden Hospital. The individual versions of the questionnaire (for groups 1, 2 and 3) are available as supplementary Table S1a, b and c.
Patient groups
This was a single centre study conducted at The Royal Marsden Hospital over a two-year period between 2016 and 2018. Participants were patients over the age of 18 who were being treated and were due for, or had previously had, imaging in one of the following three contexts:
Group 1: Currently enrolled in a research study involving imaging (MRI and/or PET/CT).
Group 2: Previously enrolled in a research study that involved imaging (MRI and/or PET/CT). Patient’s involvement in the research study had ended.
Group 3: Currently undergoing imaging (MRI and/or PET/CT) as part of their standard clinical care. No previous imaging as part of a research study.
Patients were eligible to participate if they met the following inclusion criteria: being treated at The Royal Marsden Hospital; over the age of 18; having imaging (MRI or PET/CT) as part of research or clinical care. Patients were excluded if they were unable to complete the questionnaire or if they had already completed a questionnaire for this study. For Group 2 patients, checks were made prior to sending out the study invitations to ensure previous participants were not deceased, to prevent causing distress. To minimise the effects of confounding variables in terms of age, gender and cancer type, recruitment was random; all eligible patients attending imaging (Groups 1 and 3)/ previously participated in imaging research studies (Group 2) who were able and willing to participate were contacted. As well as directly approaching patients, a poster advertising the study was displayed in the imaging department and questionnaires were available for patients to take to enable their participation.
Potential participants attending the MRI and PET/CT departments for scanning were approached individually by members of the study team, radiographers and trial coordinators, who administered the questionnaires. Participants were provided with a PIS explaining the rationale of the study and what their participation involved. Completed questionnaires, collected at the department reception desks, were only accepted if written consent was also provided. Patients in Group 1 completed the questionnaire after attending their first research scan. Group 2 patients were sent the information via post, along with a letter of invitation to participate and a pre-paid return envelope. Group 3 patients completed the questionnaire after their clinical scan. The study trial coordinator maintained a log of completed questionnaires.
Data analysis
The aim of this study was to capture the factors that influence participation in trials involving imaging, namely MRI and PET/CT. Patient responses were collated from completed questionnaires and analysed by group using summary descriptive statistics. Formal testing for differences between groups was not performed, as it would not have provided additional meaningful information.