Benefits, Challenges and Potential Strategies of Open Source Health Economic Models

A common criticism of the pharmaceutical industry is that it fails to achieve transparency [1, 2]. To allay concerns, the industry needs to collaborate openly with stakeholders to make medicines widely available and affordable—this will mean companies need to address some of their practices [1, 3, 4]. We suggest that an important practice to address is the presentation of health economic models. Formal health economic models are commonly used to support decision makers when deciding whether funding particular pharmaceuticals will improve the health of a population [5, 6]. The value of a formal model lies not only in its results but also in the revelation of the assumptions about both the data and the logical relationships it embodies [6]. Presented properly, the model provides clarity on key issues. The value of adopting the correct modelling methodology has been recognised by national and international bodies who have issued guidance for developing models; for example, the reports generated from the recent US Panel on Cost-Effectiveness in Health and Medicine [7] and the collaboration between the International Society for Pharmacoeconomics and Outcomes Research and the Society of Medical-Decision Making (ISPOR-SMDM) [8, 9]. Similarly, the European Network for Health Technology Assessment (EUnetHTA) is also working towards international level collaboration, providing a core health technology assessment (HTA) model framework and a guide to best practices [10]. Multiple guidelines can produce some inconsistencies [5, 10–14] but they have helped produce some clarity in dealing with uncertainty and validating and reporting models transparently [9]. Despite these welcome developments, individual models developed in the same therapeutic area may be significantly different from one another. Occasionally, efforts have been made to standardise them [15]. However, standardisation is not the norm and, in our experience, a model code is rarely shared. It is not just pharmaceutical companies that have been challenged regarding the level of information shared. For example, the UK National Institute of Health and Care Excellence and the US Institute for Clinical and Economic Review are involved in debates around the extent their health economic models should be made publicly available [16, 17]. To facilitate this transparency, there is suggestion in the literature that open source modelling is desirable [8, 9]. The definition of open source can vary by discipline [18–21]. An open source health economic model is defined here as one that is available to those who wish to access it. This means that the model, its underlying code and a written report describing its aim, methods, structure and results would all be accessible [8]. This could be in a fully public space (e.g. freely downloadable on the Internet) or only readily available to those who request it with conditions attached to access. An open source culture allows existing models to be updated to answer new research questions and decision & Nicola Mason nmason@bresmed.com