Introduction: A multi-site randomized controlled trial was carried out between 2015
and 2019 to evaluate the impacts on quality of life of an intradialytic exercise
programme for people living with chronic kidney disease. This included a qualitative
process evaluation which gave valuable insights in relation to feasibility of the trial
and of the intervention in the long-term. These can inform future clinical Trial
design and evaluation studies.
Methods: A constructivist phenomenological approach underpinned face-to-face,
semi-structured interviews. Purposive recruitment ensured inclusion of participants in
different arms of the PEDAL Trial, providers with different roles and trial team
members from seven Renal Units in five study regions. Following ethical review,
those willing took part in one interview in the Renal Unit. Audio-recorded interviews
were transcribed (intelligent verbatim) and inductively thematically analyzed.
Results: Participants (n = 65) (Intervention arm: 26% completed; 13% who did not; Usual
care arm: 13%; 46% women; 54% men; mean age 60 year) and providers (n = 39) were
interviewed (23% PEDAL Trial team members). Three themes emerged: (1)
Implementing the Intervention; (2) Implementing the trial; and (3) Engagement of the
clinical team. Explanatory theory named “the Ideal Scenario” was developed,
illustrating complex interactions between different aspects of intervention and trial
implementation with the clinical context. This describes characteristics likely to
optimize trial feasibility and intervention sustainability in the long-term. Key aspects
of this relate to careful integration of the trial within the clinical context to optimize
promotion of the trial in the short-term and engagement and ownership in the longterm. Strong leadership in both the clinical and trial teams is crucial to ensure a
proactive and empowering culture.
Conclusion: Novel explanatory theory is proposed with relevance for Implementation
Science. The “Ideal Scenario” is provided to guide trialists in pre-emptive and
ongoing risk analysis relating to trial feasibility and long-term intervention
implementation. Alternative study designs should be explored to minimize the
research-to-practice gap and optimize the likelihood of informative findings and
long-term implementation. These might include Realist Randomized Controlled Trials
and Hybrid Effectiveness-Implementation studies.