ANÁLISIS DE ASPECTOS INTERNOS

Development and implementation of the intervention

We have fully described not only what the intervention is and how it was developed, often poorly

reported,221_{but also how implementation and context affected its feasibility and acceptability.}131,222_{There is}

any case, may not be important until finalising an intervention’s specifications.223_{Our development group}

contained too few parents of boys with DMD to reflect a broad range of concerns or to exercise an effective voice, and no community physiotherapists. Future development of AT programmes should fully and effectively involve these and other stakeholder groups, such as charities. Time prohibited iterative testing and adjustment before the pilot224,225_{may have improved the intervention. The study team made it}

insufficiently clear to physiotherapists that they should generate a focused and achievable prescription to guide intervention sessions, leading to suboptimal prescriptions in five boys. Although all participating physiotherapists had been on a Chartered Society of Physiotherapy AT foundation course and received a training video, we are not clear how many watched it and not all took up face-to-face training.

The pilot trial

Pilot trials are not designed or powered to provide estimates of clinical effect that are adequate for decision-making.70,71_{We measured key process variables,}70_{describing fidelity, dose and reach;}132_{the study}

was not powered to test quantitatively for mechanisms of impact or the presence of contextual moderators.131

As a result of the shortfall in recruitment, data are also inadequate for sample size estimation.226_{Although the}

consent/assent process was procedurally correct, participant recall of it was poor (seeChapter 5,Appraisal work), indicating that improvements are necessary in any further related research (seeChapter 9).

The decision to deliver AT outside its usual context of delivery by community physiotherapists in community pools to delivery by specialists in specialist centres was taken for the best of reasons. The national

reorganisation of services in 2013 (seeChapter 3,Problems with the delivery of land-based therapy) left us lacking in confidence that we would be able to approach and engage the right people to set up the study. Although we have fully described the context of access and delivery, the evaluation we have delivered is of a decontextualised intervention. Many of the barriers that we encountered in the delivery of AT may not be encountered to the same extent if the intervention were to be delivered more locally to the service user and in community settings.

The clinical assessments focused on physiological function and paid insufficient attention to participation outcomes, the importance of which emerged during qualitative research and in consultation with PPI representatives. Agreed approaches to the conceptualisation and measurement of participation have been lacking,97,98,100_{but two reviews and a conceptual framework}100,227_{now provide sound guidance for}

future research.

The qualitative research

The use of qualitative methods successfully captured breakdowns in implementation and views on the intervention131_{and enabled us to recommend changes to the intervention. The use of a logic model,}

published empirical evaluations and social science theory ensured that key uncertainties and important questions were addressed.131_{Iterative data collection enabled the exploration of emergent themes. We did}

not use serial interviews to capture changes in the intervention or related experiences over time,131,228_{or to}

adequately explore the relationship between families, community physiotherapists and schools.

Optimisation

As physiotherapy is a process that is poorly understood by analytical reasoning and requires extensive knowledge-based processing, it is not generally helpful to standardise it.136_{The decision to evaluate}

optimisation rather than fidelity of delivery was appropriate and ensures congruence with the intervention theory.139,229,230_{The use of an experienced independent physiotherapist with content expertise was}

appropriate, but might have been improved by a second rater working blind to the assessment of the first. Only two of the therapists took up the opportunity to respond to the independent assessment of their work; protocolisation and better scheduling of this opportunity might help to bring out important nuances in future optimisation exercises. We are unclear how adherent most participants were to their LBT

exercises; it is plausible that we have good-quality data only on those who were able to comply both with their LBT prescription and with study procedures.

Health economics

This study has shown that the potential investment costs for families could be greater than those to the NHS. However, patients and carers were happy to commit to AT. Owing to the small numbers in this study, these findings have focused on the cost of delivery of the intervention and the impact on families; we have not been able to take into account variability in any assumptions, although we have reported ranges when applicable. In addition, we have not been able to use information on the CHU-9D and additional resource use owing to the small numbers and the lack of any meaningful interpretation.

Although we have not used the information the study showed, it was feasible to collect it in this population.

Triangulation protocol

We selected a different method appropriate to the commissioning brief,131_{but did not implement methods}

independently.231_{A formal mixed-methods approach allowed the robust use of qualitative data used to}

explain quantitative findings.