A methodological framework for developing conceptual models in economic evaluation Health Economics and Health Technology Assessment (HEHTA) N McMeekin, A Briggs, O Wu HEHTA, Institute for Health and Wellbeing, University of Glasgow N McMeekin, A Briggs, O Wu HEHTA, Institute for Health and Wellbeing, University of Glasgow 1 Introduction 2 Methods Conceptual models are a simplification of a real-world system in visual form, illustrating hypothesised relationships In other fields (such as ecology and engineering) conceptual models are routinely used, as witnessed by the availability of methodological frameworks in these areas In the field of economic evaluation conceptual modelling is primarily seen as a stage in the mathematical modelling process, however a conceptual model can be used in its own right The benefits of using of conceptual model in economic evaluation are twofold: as a communication tool and to guide the analysis and interpretation of results There is a lack of systematic guidance for conceptual modelling in economic evaluation, and all existing guidance focusses on mathematical model development The aim of this research was to produce a conceptual modelling framework to systematically guide the development of a conceptual model for economic evaluation, not based on mathematical modelling We combined guidance from conceptual modelling frameworks in fields outwith economic evaluation in developing our framework Figure 1: Methods employed to develop the proposed framework 3 Proposed framework Figure 2: Proposed framework 4 Results 5 Discussion The proposed framework is presented in Figure 2 above It consists of three phases: 1) getting to know the bigger picture, 2) developing the conceptual model, and the final phase of 3) wrapping up These three phases are further broken down into seven smaller stages The arrows on Figure 2 depict how the proposed framework guides us through the stages of developing a conceptual model, but these stages will be revisited iteratively as the conceptual model develops The conceptual model should be kept simple, so it is clear and understandable, but complex enough to answer the research question Our framework offers systematic guidance for developing conceptual models in economic evaluation, independent to mathematical modelling. The full guidance consists of a ‘recommendation’ and ‘explanation’ section for each stage. Developing a conceptual model a priori assists in communication with the study or project team, aiding understanding of the economic evaluation process and ensuring the conceptual model is accurate. A conceptual model can be used to guide the analysis, highlighting key resource use areas and hypothesized relationships Contact details: Nicola McMeekin. Email nicola.mcmeekin@glasgow.ac.uk