'Translational formative evaluation': critical in up-scaling public health programmes.

The process of generating evidence-based public health interventions is understood to include steps that define the issue, generate and test solutions in controlled settings, replicate and then disseminate more widely. However, to date models have not considered the types and scale of formative evaluation tasks that are needed to up-scale interventions, from efficacy to population-wide dissemination in the real world. In this paper, we propose that an additional stage of 'translational formative evaluation' is necessary for the translation of effectiveness evidence into wide-scale public health practice. We illustrate the utility of translational formative evaluation, through a case study of the Get Healthy Information and Coaching Service(®) (GHS), a population-based telephone service designed to assist adults change lifestyle-related behaviours. The additional translational formative evaluation steps comprised synthesis of efficacy studies, qualitative research with the wider target audience, environmental analysis and stakeholder consultation. They produced precise recommendations to refine GHS design and implementation. Translational formative evaluation is a necessary intermediate step, following efficacy studies and a precursor to population-wide implementation of public health programmes.