Developing a timeline for evaluating public health nutrition policy interventions: What are the outcomes and when should we expect to see them?

Objective: To develop a timeline for evaluating public health nutrition policy
interventions.
Design: Concept mapping, a stakeholder-driven approach for developing an
evaluation framework to estimate the ‘time to impact’ for policy interventions.
The Schools (Health Promotion and Nutrition) (Scotland) Act 2007 was used as
the model to develop the evaluation timeline as it had typical characteristics of
government policy. Concept mapping requires stakeholders to generate a list of
the potential outcomes, sort and rate the outcomes. Multidimensional scaling and
hierarchical cluster data analysis were used to develop an anticipated timeline to
impact for the policy.
Setting: United Kingdom.
Subjects: One hundred and eleven stakeholders representing nutrition, public
health, medicine, education and catering in a range of sectors: research, policy,
local government, National Health Service and schools.
Results: Eighty-five possible outcomes were identified and grouped into thirteen
clusters describing higher-level themes (e.g. long-term health, food literacy,
economics, behaviour, diet, education). Negative and unintended consequences
were anticipated relatively soon after implementation of the policy, whereas
positive outcomes (e.g. dietary changes, health benefits) were thought likely to
take longer to emerge. Stakeholders responsible for implementing the legislation
anticipated that it would take longer to observe changes than those from policy or
research.
Conclusions: Developing an anticipated timeline provides a realistic framework
upon which to base an outcome evaluation for policy interventions and identifies
positive and negative outcomes as well as considering possible unintended
consequences. It offers benefit to both policy makers and researchers in mapping
the progress expected towards long-term health goals and outcomes.