Adherence
As HOMESIDE dyads live complex lives, it is unlikely that all dyads will adhere to the 12-week intervention. Adherence to the MI/RI intervention will be measured first through CG completed diaries, collecting the number of sessions and the time per session per week. If a dyad supplies a range (e.g. 20–30 min) for the time in a diary entry, the lower limit (i.e. 20 min) will be used for the duration of that day. For dyads with incomplete or missing entries in the diary, we will use the information from the phone call guidelines to measure adherence to the intervention, collecting how often they have been using the programme at each phone call in weeks 2, 5, 7, 9 and 11.At any given week during the intervention, dyads are deemed adherent if they have reported a minimum of 2 sessions in the completed diaries across the intervention period (i.e. 7 to 90 days post-randomisation). The first week will not be included in the calculation of adherence as it includes the first training session, which may have been held at the end of the week for some dyads. Adherence to the intervention will be derived by summing the number of weeks dyads are deemed adherent across the intervention period. Dyads will be deemed adherent if they scored at least 10 (i.e. a minimum of 10 weeks in which they adhered) and did not have more than two consecutive weeks in which they do not report any engagement with the programme. For dyads who may not be adherent due to incomplete or missing information in the diary, we will use the data captured in the phone call guidelines and consider the dyad adherent if they answered that they have been using the programme 2 days per week or more at all 5 weeks.Information on the current use of music and reading in daily life at follow-up at 90 and 180 days post-randomisation, irrespective of the randomised intervention, will be summarised by treatment group.