Description of feasibility measures
| Feasibility component | Measure | Described as |
| Recruitment | Recruitment rate | The number of dyads consented/number eligible |
| Attrition | Attrition rate | The number of dyads withdrawn/number consented |
| Therapy adherence | Therapy log (companion's diary) | The total dose (frequency and duration) of the intervention delivered, recorded by the companion after each session |
| Acceptability of therapy | Therapy log (companion's diary) | Companions will rate the extent to which (in each session) the participant was interested, motivated, gained a sense of achievement; took the initiative and displayed emotional responses. Ratings will be made on a 5-point Likert scale on which ‘1’= strongly disagree and ‘5’=strongly agree. |
| Acceptability of assessments | Interview record form/focus group | Mixed methods. Quantitative data will include response rates, time taken and level of missing data. Qualitative investigation (assessors interview record form/focus group with blinded assessor) will explore the process: how were the assessments administered, queries raised by respondents, respondents’ markings on the instrument, practical difficulties observed and strategies employed to overcome challenges. |