Enabling the transferability of complex interventions: exploring the combination of an intervention's key functions and implementation.

Objectives: Several public health interventions are not described, not evaluated and not transferred. The objective was to assess the feasibility and acceptability of using a description model making a distinction between interventions' transferable elements, and those that are more context-specific, to make their evaluation and transferability easier.

Methods: The theoretical distinction between an intervention function and its form in a specific context has been empirically explored. A community-based intervention (named "Ciné-Ma-Santé") has been described, using a "key function/implementation/context" model. This process has been co-constructed through qualitative research and knowledge exchange process between project leaders and researchers from different disciplines.

Results: The use of the model proves feasible and useful for both project leaders and researchers. Nine key functions were described, as well as their implementation and the features of the intervention context.

Conclusions: Rendering explicit key functions of public health interventions could constitute a useful step to their evaluation and transfer. It enables the formulation of hypotheses regarding the potentially standardizable elements of interventions, and elements that can be modified while maintaining the integrity of the intervention.