Dealing with context in logic model development: Reflections from a realist evaluation of a community health worker programme in Nigeria

Highlights • We describe the process of developing a logic model as part of an ongoing realist evaluation of a community health workers programme in Nigeria. • We also reflect on how other scholars explored context during logic modelling in theory-driven evaluations of complex healthcare programmes. • Creating a logic model is a key step in modelling relations between a programme, its outcomes and contextual conditions that can affect outcomes. • Logic models can also inform identification of initial working theories and evaluation measures for verifying underlying programme theories. • Lessons for researchers and programme planners who wish to develop and use logic models in future evaluations are discussed.
Logic models (LMs) have been used in programme evaluation for over four decades. Current debate questions the ability of logic modelling techniques to incorporate contextual factors into logic models. We share experience of developing a logic model within an ongoing realist evaluation which assesses the extent to which, and under what circumstances a community health workers (CHW) programme promotes access to maternity services in Nigeria. The article contributes to logic modelling debate by: i) reflecting on how other scholars captured context during LM development in theory-driven evaluations; and ii) explaining how we explored context during logic model development for realist evaluation of the CHW programme in Nigeria. Data collection methods that informed our logic model development included documents review, email discussions and teleconferences with programme stakeholders and a technical workshop with researchers to clarify programme goals and untangle relationships among programme elements. One of the most important findings is that, rather than being an end in itself, logic model development is an essential step for identifying initial hypotheses for tentative relevant contexts, mechanisms and outcomes (CMOs) and CMO configurations of how programmes produce change. The logic model also informed development of a methodology handbook that is guiding verification and consolidation of underlying programme theories.