Public health: a practical approach to programme evaluation

Start with a logic model

Before evaluating any programme, map its logic: what resources go in, what activities happen, and what short-, medium-, and long-term outcomes are expected. This "theory of change" makes it possible to choose indicators that actually reflect programme goals, rather than whatever data happens to be available.

Choosing the right evaluation design

• Process evaluation asks whether the programme was delivered as planned—reach, fidelity, and participant experience.
• Outcome evaluation asks whether the intended changes occurred, often using baseline and endline surveys.
• Impact evaluation asks whether the programme caused the change, which usually requires a comparison group or a strong quasi-experimental design.

Working with limited data

Many public health programmes do not have the budget for a randomised design. Practical alternatives include:

• Pre-post comparisons with a matched comparison site.
• Interrupted time-series analysis using routine surveillance data.
• Mixed-methods approaches that pair quantitative indicators with qualitative interviews to explain why results look the way they do.

Reporting for decision-makers

Policy and programme audiences need a clear answer to "so what should we do differently?" alongside the technical findings. A short executive summary with explicit recommendations is often more influential than the full technical report.