In the last blog we explained what prevention means for public health and for the community food sector. In this blog post we explain how it can be evaluated.

Earlier this year, Evaluation Support Scotland (ESS) delivered a workshop for the community food sector on evaluating prevention. One of the key messages was that although prevention can be difficult to measure, it is possible to understand and evaluate how your work contributes to preventing poor health and reducing inequalities. ESS suggests using these steps:   

1. Clarify what you’re preventing and for whom.
2. Identify protective factors to generate positive outcomes.
3. Create a theory of change (such as by using a logic model or other tools to help you map out or understand how the activities you do help achieve positive outcomes).
4. Evaluate your outcomes.

Here’s these steps in more detail:

1. Clarify what you’re preventing and for whom
Start by identifying the specific problem you’re trying to address and who is affected by it.

For example, a CFI such as a community café may aim to help parents on low incomes who struggle to access affordable, nutritious food locally. Understanding what’s contributing to the problem, such as low income, limited transport or a lack of affordable food outlets, helps clarify where your work fits.

2. Identify protective factors
Prevention is often about strengthening the things that help people stay well and avoid current or future problems.

In the example above, parents who struggle to access affordable food may benefit from protective factors such as:

• Reliable, regular and affordable transport
• Nearby shops or cafés selling affordable, nutritious food
• Adequate income through benefits or fair paid work
• Social and supportive local connections with friends, family, services or community groups to help, for example with getting to the shops, sharing supermarket delivery costs or sharing the preparation of family meals.

While it’s difficult to measure a problem that hasn’t happened yet – such as the impact on parents’ longer-term health, you can measure whether people have gained these protective factors.

3. Develop a theory of change
A theory of change helps map how your activities contribute to positive outcomes.

A simple way to think about it is:

Here’s a couple of simple CFI examples:

The impact of your activity might not stop at providing a varied diet/ less isolation. This can be built on depending on the capacity of the organisation, such as:

These examples highlight the importance of being clear about what your activities are likely to influence and where their contribution may be more limited: Affordable meals can improve access to food, but not necessarily overall diet quality.

It is also important to consider wider influences on outcomes. CFIs contribute to change alongside other organisations, services and broader social and economic factors. People’s circumstances can change over time, affecting outcomes and the extent to which protective factors are maintained. Focusing on how your work contributes to outcomes rather than trying to prove direct causation makes evaluation more realistic and manageable.

Developing a theory of change can help you map how your activities are expected to contribute to change, identify assumptions, and consider factors beyond your control. Tools such as logic models and Weaver’s Triangles can support this process.

Developing a theory of change is not always straightforward. Working with colleagues, partners and community members can help build a shared understanding of how change happens and where your activities fit within a wider system.

4. Evaluate your outcomes
You can evaluate how your CFI contributes to prevention by gathering evidence about whether intended outcomes have been achieved. Evaluation Support Scotland provides practical resources on planning and evaluating activities, understanding outcomes and indicators, and collecting meaningful evidence. Their guidance also highlights the importance of proportionate evaluation, using approaches that are appropriate to your organisation’s capacity and the needs of participants.

Further resources
ESS resource on logic models and Weaver’s Triangle: ESS-LM-1c-Logic-model-guide-March-2022.pdf

ESS resource on Recognising our rich tapestry: measuring the contribution of third sector organisations to tackling health inequalities – Evaluation Support Scotland