It has increasingly become de rigueur – if not necessary – to publish the primary data collected as part of clinical trials and other research endeavours. In 2015 for example, the British Medical Journal stipulated that a pre-condition of publication of all clinical trials was the guarantee to make anonymised patient-level data available on reasonable request. Data repositories, from which data can be requested such as the Yoda Project, and from which data can be directly downloaded such as Data Dryad provide a critical service for researchers wanting to make their data available and transparent. The UK Data Service also provides access to an extensive range of quantitative and, more recently, qualitative data from studies focusing on matters relating to society, economics and populations. Publishing data enables others to replicate and verify (or otherwise) original findings and, potentially, to answer additional research questions and add to knowledge in a particularly cost-effective manner.
At present, there is no requirement for health economic models to be published. The ISPOR-SMDM Good Research Practices Statement advocates publishing of sufficient information to meet their goals of transparency and validation. In terms of transparency, the Statement notes that this should include sufficiently detailed documentation “to enable those with the necessary expertise and resources to reproduce the model”. The need to publish the model itself is specifically refuted, using the following justification: “Building a model can require a significant investment in time and money; if those who make such investments had to give their models away without restriction, the incentives and resources to build and maintain complex models could disappear”. This justification may be relatively hard to defend for “single-use” models that are not intended to be reused. Although the benefits of doing so are limited, publishing such models would still be useful if a decision-maker facing a different cost structure wanted to evaluate the cost-effectiveness of a specific intervention in their own context. The publication of any economic model would also allow for external validation which would likely be stronger than internal validation (which could be considered marking one’s own homework).
The most significant benefits of publication are most likely to arise from the publication of “general” or “multi-application” models because those seeking to adapt, expand or develop the original model would not have to build it from scratch, saving time and money (recognising this process would be facilitated by the publication of the technical documentation from the original model). Yet it is for these models that not publishing gives developers a competitive advantage in any further funding bids in which a similar model is required. This confers partial monopoly status in a world where winning grant income is becoming ever more critical. However, I like to believe most researchers also want to maximise the health and wellbeing of society: am aim rarely achieved by monopolies. The argument for publication gets stronger when society has paid (via taxation) for the development of the original model. It is also possible that the development team benefit from publication through increased citations and even the now much sought after impact. For example, the QRISK2 calculator used to predict cardiovascular risk is available online and its companion paper  has earned Julia Hippisley-Cox and colleagues almost 700 citations.
Some examples of published economic models exist, such as a costing model for selection processes for speciality training in the UK. While publication of more – if not all – economic models is not an unrealistic aim, it is also necessary to respect intellectual property rights. We welcome your views on whether existing good practice for transparency in health economic modelling should be extended to include the model itself.
— Celia Taylor, Associate Professor
- Loder E, & Groves T. The BMJ requires data sharing on request for all trials. BMJ. 2015; 350: h2373.
- Eddy DM, Hollingworth W, Caro JJ, et al. Model transparency and validation: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force–7. Med Decis Making. 2012; 32(5): 733-43.
- Hippisley-Cox J, Coupland C, Vinogradova Y, et al. Predicting cardiovascular risk in England and Wales: prospective derivation and validation of QRISK2. BMJ. 2008; 336(7659): 1475-82.