Methods in Systematic Reviews of Health Economic Evaluations in Submissions to Health Technology Assessment Agencies: How Systematic Are They, and Does This Matter?

Systematic reviews of health economic evaluations (SR-HEEs) are perceived as mandatory components of the health technology assessment (HTA) process in many jurisdictions. However, HTA agencies vary in how they prescribe reviews of HEEs should be conducted and the explicit purpose they serve. This article identifies the requirements of prominent HTA agencies, reports on the real-world conduct of SR-HEEs by health technology developers (HTDs), and explores their utility in the HTA process. International HTA guidelines were consulted, alongside a targeted review of SR-HEEs submitted to the National Institute for Health and Care Excellence (NICE) in 2024. While a systematic approach is a constant requirement to reviews of HEEs, it is defined inconsistently across agencies, with clinical and safety systematic reviews (SRs) receiving more rigid prescription. Consequently, SR-HEEs submitted to NICE demonstrated mixed methods. Despite these pragmatic deviations of SR-HEEs, External Assessment Groups (EAGs) raised no major concerns, and reimbursement decisions do not appear to be influenced. Our findings suggest a rigor gap between SR theory and practice, driven by the inherent heterogeneity of economic models, which renders quantitative pooling inappropriate. We submit that a more pragmatic approach to reviews of HEEs would be appropriate for HTA. To maximize utility and reduce resource waste, we propose a two-stage framework: early pragmatic "landscape mapping" to inform early model conceptualization, followed by a formal SR-HEE only when a specific useful research question is identified. This strategic realignment, possibly supported by emerging technologies, would enable HTA resources to be reallocated toward higher-value activities.