Getting messier with TIDieR: embracing context and complexity in intervention reporting.

Background: The Template for Intervention Description and Replication (TIDieR) checklist and guide was developed by an international team of experts to promote full and accurate description of trial interventions. It is now widely used in health research. The aim of this paper is to describe the experience of using TIDieR outside of trials, in a range of applied health research contexts, and make recommendations on its usefulness in such settings.

Main Body: We used the TIDieR template for intervention description in six applied health research projects. The six cases comprise a diverse sample in terms of clinical problems, population, settings, stage of intervention development and whether the intervention was led by researchers or the service deliverers. There was also variation in how the TIDieR description was produced in terms of contributors and time point in the project. Researchers involved in the six cases met in two workshops to identify issues and themes arising from their experience of using TIDieR. We identified four themes which capture the difficulties or complexities of using TIDieR in applied health research: (i) fidelity and adaptation: all aspects of an intervention can change over time; (ii) voice: the importance of clarity on whose voice the TIDieR description represents; (iii) communication beyond the immediate context: the usefulness of TIDieR for wider dissemination and sharing; (iv) the use of TIDieR as a research tool.

Conclusion: We found TIDieR to be a useful tool for applied research outside the context of clinical trials and we suggest four revisions or additions to the original TIDieR which would enable it to better capture these complexities in applied health research: An additional item, 'voice' conveys who was involved in preparing the TIDieR template, such as researchers, service users or service deliverers. An additional item, 'stage of implementation' conveys what stage the intervention has reached, using a continuum of implementation research suggested by the World Health Organisation. A new column, 'modification' reminds authors to describe modifications to any item in the checklist. An extension of the 'how well' item encourages researchers to describe how contextual factors affected intervention delivery.