For any intervention a programme theory can be articulated that explains how the programme designers expect it to work. Making these assumptions explicit generates a programme theory that can be tested and refined and helps to identify the full spectrum of possible impacts of the intervention. We are currently building the theory of change for SH24.

By interviewing a range of stakeholders involved in SH24 we are documenting their views on the range of impacts that might result from the implementation of SH24 and the causal chain that leads to each outcome. This work is already generating rich insights. It shows how SH24 might respond to the needs of a range of different users. For example, existing clinic based service users without symptom might want rapid, convient access to tests for sexually transmitted infection and those with more complex needs might require telephone support from SH24 between clinic visits. SH24 could effectively meet the needs of both of these groups of users.