Implementation fidelity in a complex intervention promoting psychosocial well-being following stroke: an explanatory...

Area of Science:

• Psychosocial Intervention Research
• Health Services Research
• Clinical Trial Methodology

Background:

• Complex interventions require process evaluations for robust RCT outcomes.
• Implementation fidelity, assessing protocol adherence, is a key component of process evaluation.
• This study focused on the implementation fidelity of a dialogue-based psychosocial intervention.

Purpose of the Study:

• To evaluate the extent to which a dialogue-based psychosocial intervention was delivered according to its protocol.
• To identify factors moderating implementation fidelity.
• To enhance confidence in RCT outcomes through process evaluation.

Main Methods:

• An explanatory, sequential two-phase mixed methods design was employed.
• Quantitative process data were collected longitudinally, complemented by post-RCT qualitative data.
• Data were analyzed using descriptive statistics, a scoring system for adherence, and theory-driven content analysis.

Main Results:

• Core intervention components were delivered, with individualized trajectories observed.
• A composite adherence score indicated 80.1% of interventions were implemented with high fidelity.
• Participant responsiveness, policy description comprehensiveness, context, and recruitment emerged as prominent moderators.

Conclusions:

• Evaluating implementation fidelity is crucial for understanding trial outcomes.
• High fidelity implementation of this intervention was achieved for the majority of participants.
• The study offers methodological insights for future process evaluations and fidelity studies.