Introduction

In recent years, there has been a growing awareness of the need for rigorous and transparent reporting of health research to ensure that studies can be reproduced.1–7 The value of health research can be improved by increasing transparency and openness of the processes of research design, conduct, analysis and reporting.8 9 Sharing data and materials from health research studies has multiple positive effects within the research community: it is part of good publication practice in keeping the principles of Open Science; it allows for the conduct of additional analyses to further explore data and generate new hypotheses; it allows access to unpublished data and it encourages reproducibility in research.10 Recognising the potential impact of open research culture, journals are increasingly supporting the use of reporting guidelines, as well as policies and technologies that help to improve transparency.11–13 Scientists are increasingly encouraged to use reproducible research practices, which allow others to perform direct replication of studies using the same data and analytic methods.14 15 Furthermore, research funders are changing their grant requirements including open data sharing.16 17

Health economic evaluations, which compare alternative interventions or programmes in terms of their costs and consequences,18 can help inform resource allocation decisions. A cost-effectiveness analysis, a specific form of economic evaluation that compares alternative options in terms of their costs and their health outcomes, is a valuable tool in health technology assessment processes. Cost-effectiveness analyses haves been promoted as an important research methodology for assessing value for money of healthcare interventions and an important source of information for making clinical and policy decisions.19 Decisions about the use of new interventions in healthcare are often based on health economic evaluations. Efforts to increase transparent conduct and reporting of health economic evaluations have existed for many years.20–30 For example, the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement,30 first published in March 2013, provides recommendations for authors, peer reviewers and journal editors regarding how to prepare reports of health economic evaluations. The aim of CHEERS is to facilitate complete and transparent reporting of health economic evaluations and help more formal critical appraisal and interpretation. As a potential measure of impact,31 CHEERS has been cited over 1000 times in the Web of Science. However, little attention has been given to reproducibility practices such as sharing of study protocols, data and analytic methods (which allow others to recreate the study findings) as part of health economic evaluation studies.22–25 29

Previous research has evaluated the impact of economic evaluation guidelines and the reporting quality of published articles. For example, Jefferson et al 32 previously investigated whether publication (in August 1996) of the BMJ guidelines on peer review of economics submissions made any difference to editorial and peer review processes, quality of submitted manuscripts and quality of published manuscripts in two high-impact factor medical journals (BMJ and T he Lancet). In a sample of 105 articles on economics submissions, 27 (24.3%) were full health economic evaluations. Although Jefferson et al 32 were not studying reproducibility, openness and transparency directly, they did undertake an assessment of the impact of a reporting guideline for health economic evaluations. A 'before and after' assessment of implementation of the guideline was performed to assess how closely the reporting guidelines were followed. The authors found that the publication of the guidelines helped the editors improve the efficiency of the editorial process but had no impact on the reporting quality of health economic evaluations submitted or published.

The primary objective of this study will be to examine the extent to which articles of health economic evaluations of healthcare interventions indexed in Medline incorporate transparency, openness and reproducibility research practices. Secondary objectives will be to explore (1) how the reporting and reproducibility characteristics of health economic evaluations change between 2012 and 2022 and (2) whether the transparency and reproducibility practices have improved after the publication of the CHEERS statement in 2013.