[Theory of change: a tool for participatory planning and evaluation in community health]

There is a growing interest in finding innovative approaches to the evaluation of complex interventions in public health. This methodological note presents the theory of change as a useful tool to facilitate both the planning and the evaluation of community health promotion interventions. A theory of change is a visual representation of how a programme or intervention works, in which its different components can be identified, together with how they relate to each other: what its objectives are, its expected results and through which actions they are expected to be achieved. It can be an applied research tool, developed using participatory approaches together with all relevant stakeholders, who can identify and jointly decide what to evaluate and how to.