Surveying knowledge, practice and attitudes towards intervention fidelity within trials of complex healthcare interventions.

Despite good awareness of intervention fidelity and its importance, poor knowledge and understanding appears to be a key factor limiting how intervention fidelity is addressed in trials of complex interventions. Participants identified a need for further training and education in this area. Additionally, clarification of the terminology, definition and components of intervention fidelity would facilitate better understanding of the concept. A discrepancy between participants' use of fidelity strategies and subsequent reporting raises concerns around inadequate fidelity reporting in the trials literature.