Table 1 Background context surrounding this study

Background: FLEX-HD feasibility trial and qualitative studies

The current qualitative study was embedded in a larger programme of research [22] which aimed to:

  - determine whether intradialytic cycling (IDC, cycle ergometry delivered during HD treatment using a bespoke static exercise bike) was feasible for people living with frailty and receiving HD

  - inform a tailored exercise intervention for this population

• Inclusion criteria for the qualitative studies:

  - receiving HD for 3 months

  - aged 18 years or older

  - classified as vulnerable to severely frail according to the Clinical Frailty Scale (CFS score 4–7)

  - able provide informed consent and speak English

  - with a history of at least one fall in the last 6 months

Who had both declined to, and had participated in, IDC.

• The qualitative studies involved three stages of data collection:

  - semi-structured interviews exploring participants experience of living with HD, frailty and falls

  - self-completed diaries gathering contemporaneous information about their experiences of falls over a period of up to three months

  - follow-up interviews exploring diary entries, experiences of participating in a trial (or reasons for declining), participants perceptions of IDC and their needs relating to exercise.