Table 1 Example semi-structured interview questions

Why did you choose to participate in the PICNIC study (the study)? How did you feel when you were approached to participate in the study?

To what extent do you believe patients and their family members should be advocating for best nutrition practice?

What did you think about the education session with the dietitian?

Were you able to ask questions, and were these answered to your satisfaction? Did you feel you could adequately report on your/the patient’s nutrition history?

How do you see the role of the patient and their family in the context of cancer care? Do you think they should be actively involved in some aspects of patient care and decision making?

Was the information provided in the booklet clear? Was it useful/ relevant? Are you able to suggest any ways in which the booklet could be improved?

Do you think providing this level of nutrition information was beneficial for patients/families?

Were you involved in recording your/your family member’s food intake on the food record? If not, why not? If so, did you find this easy or difficult? Were there any advantages/ disadvantages to keeping the booklet? Why?

Did you notice whether patients or families were completing the food intake chart? Why or why not do you think they completed it? Can you see any barriers/facilitators to patients/ families completing the food chart? Do you think it’s beneficial for them to complete it? Can you see any ways of making the food chart completion easier for patients/families?

Did you ask health care staff questions about your/your family member’s nutrition? If yes, do you think staff were receptive to these questions?

Did you feel comfortable having these conversations with staff?

Did patients or their family members make specific enquiries about nutrition? Do you think patients and families who participated in the study asked more questions of the staff than families that didn’t?

Patients: What did you think about involving your family in this intervention? Do you think your family member was a positive support in your nutrition? Did you have any issues with your family member(s) being involved?

Family members: Do you think you could tell whether your family member was eating enough?

Do you think this intervention (i.e. session with the dietitian, asking patients/families to complete food charts, and encouraging patients/families to be active participants in their nutrition care) is feasible in real practice?

Overall, do you think this intervention helped with your/your family member’s nutrition? Why/why not? Would you participate in something like this again? Why/why not?

Can you comment on the intervention overall? Is there anything you would change?