institutional factors, such as in health and medicine (14). Conjoint analysis has been applied successfully to measuring preferences for a diverse range of health applications. Examples range from cancer treatments (15), HIV testing (16) and treatment (17), dermatology services (18), asthma medications (19), genetic counseling (20), weight-loss programs (21), insulin therapy in type 2 diabetes (22), diabetes prevention programs (23), colorectal cancer screening (24), and treatments for Alzheimer’s disease (25).
Developing the Checklist
The ISPOR Conjoint Analysis in Health Good Research Practices Task Force met regularly over the course of 24 months to identify the important stages of a conjoint analysis, to discuss good research practices for conjoint analysis, and to develop and refine the final checklist. ISPOR members were engaged in the development of the checklist through multiple sessions at ISPOR conferences (both at the International Meetings and European Congress), presentations at the first and second Conjoint Analysis in Health Conferences, and via the ISPOR web site. The final format of the checklist was then modeled after the ten-point checklist for cost-effectiveness analysis developed by Drummond and colleagues (26). Each item on the checklist is supplemented with key references, potential pitfalls, and recommendations for good research practices.
How should the checklist be used?
This checklist should be used to aid those new to conjoint analysis to understand the stages involved in producing good research. It also will be of benefit to those reviewing, reading, or otherwise assessing the validity of an application of conjoint analysis in health and medicine. By outlining a systematic process of good research practices for applying conjoint analysis – from formulating the research question through the presentation of the research (either in presentation, abstract, or manuscript) – we aim to facilitate the research process and to highlight important issues that often are neglected or poorly executed. In producing the checklist, we aimed to be as inclusive as possible – both in term of the accessibility to a broad readership and applicability to a variety of conjoint analysis methods. We have aimed at highlighting “good research practices” rather than “best research practices”. Hence we have written in a non-technical way, with many elements of the checklist presenting “food- for-thought” rather than a necessary or sufficient argument for research excellence.
We caution readers, and especially peer reviewers, that given the variety of conjoint analysis methods, a single standard of best practice is likely not to exist for many aspects of conjoint analysis and a pluralistic approach to review is needed. Throughout this report we encourage researchers to provide and reviewers to expect explanation and justification of the methods chosen to complete any given study, rather than promote any specific method. Like any contribution in health and medicine, the goal of good scientific practice is possible replication of the results. Thus, it often is more important to know what was done, rather than why it was done. While we do not advocate that the checklist be used to score articles – we specifically did not argue for a scoring method for the checklist or any threshold of acceptability – we acknowledge that it might be used in that way. Our hope is, however, that the checklist is used as means to promote more high-quality applications and subsequent publications of conjoint analyses in health and medicine, and not as a hurdle to publishing.
ISPOR Conjoint Analysis in Health Task Force Report