Table 3 Proposed TFA methods applicable to the full complex intervention development and evaluation cycle
Development phase | Pilot and feasibility phase (before going to full scale trial) | Evaluation phase (trial context) | Implementation phase (scalability) |
|---|---|---|---|
Qualitative | Qualitative | Qualitative | Qualitative |
E.g. Semi-structured interviews or focus groups based on the TFA constructs with stakeholders to help guide decisions about the form, content and delivery mode of the proposed intervention components. | E.g. Semi-structured interviews or focus groups based on the TFA constructs with potential intervention recipients and deliverers. These should focus on the anticipated acceptability of content and mode of delivery of the intervention. Analysis may reveal aspects of intervention to modify. | E.g. Semi-structured interviews or focus groups on the TFA constructs with intervention recipients and deliverers about anticipated and/ or experienced acceptability. For a longitudinal analysis acceptability semi-structured interviews or focus groups should be conducted pre-intervention, during the intervention delivery period (concurrent) and post- intervention. E.g. Reflective diary entries, applying the TFA construct labels for experienced acceptability to guide participant diary entries. | E.g. Semi-structured interviews or focus groups based on the TFA constructs to assess experienced acceptability of the intervention/ service for recipients and deliverers. E.g. Reflective diary entries, applying the TFA construct labels for experienced acceptability to guide participant diary entries |
Quantitative | Quantitative | Quantitative | Quantitative |
E.g. Questionnaires or visual analogue rating scales based on the TFA constructs to assess anticipated acceptability amongst potential intervention deliverers or recipients. | E.g. Questionnaires or visual analogue rating scales based on the TFA constructs to assess anticipated acceptability amongst potential intervention deliverers or recipients. These measures should focus on the anticipated acceptability of content and mode of delivery of the intervention. Analysis may reveal aspects of intervention to modify. | E.g. Questionnaires or visual analogue rating scales based on the TFA constructs to assess experienced and/ or anticipated acceptability for intervention recipients and deliverers. For a longitudinal analysis acceptability measures should be administered pre-intervention, during the intervention delivery period (concurrent) and post- intervention. | E.g. Questionnaires or visual analogue rating scales on the TFA constructs to assess the experienced acceptability of the intervention/ service for recipients and deliverers. |