Undertaking health economic modelling to compare in vitro diagnostics (IVDs) with imaging tests in health technology assessment (HTA) is associated with several challenges. Ignoring these challenges can lead to inaccurate and misleading results. This research identified common challenges and developed practical recommendations for considering them. An iterative, multi-methods approach was taken, including a methods review of HTA submissions, journal articles and published reports; a workshop; and semi-structured interviews with experts in health economic modelling of diagnostics. Key challenges and potential solutions were identified in the methods review and expanded in the workshop. Interviews were conducted to validate and refine challenges and practical recommendations. Recommendations were scored (from 1 strong disagreement to 5 strong agreement) by experts before and after the interviews. Final recommendations had a median score ≥ 4 (post-interview). 85 challenges (from the methods review) were prioritised into 21 with 57 recommendations after the workshop. After the interviews, recommendations were categorised into those for overcoming general challenges or challenges arising from specific aspects of the value proposition. Overall, 19 challenges with 30 recommendations are presented. To our knowledge, this is the first study investigating challenges to health economic modelling when comparing IVDs with imaging tests in HTA. The recommendations cover several topics, including variability in the diagnostic pathway, uncertain data or lack of evidence, incidental findings, and capacity constraints. Our recommendations present non-binding, guiding principles for good practice. Researchers should judge the applicability of each challenge and consider those recommendations carefully.
Watts et al. (Fri,) studied this question.