A Conceptual Analysis of the Epistemological Tension Between Positivism and Constructivism in Health Technology Assessment and Impact on Clinical Practice

Rationale. Evidence-based medicine (EBM) and health technology assessment (HTA) rest on a positivist epistemology in which value is treated as objective, measurable and generalisable across populations. This framing struggles to represent how individual patients construct the meaning and value of health states. Aims and Objectives. To analyse the epistemological tension between positivist and constructivist approaches to evidence, value and decision-making in EBM and HTA, and to examine its consequences for clinical practice and reimbursement. Method. Conceptual analysis. A philosophical account of positivism and constructivism was combined with six illustrative clinical vignettes drawn from clinical practice and selected to make the tension visible, and each vignette was mapped onto the methodological rules that govern HTA. Results. Across the vignettes, valid positivist endpoints (survival, relapse rates, quality-adjusted life years) systematically diverged from what individual patients valued (dignity, identity, meaning, cultural belonging). Utility weights, surrogate endpoints and cost-effectiveness rules could not represent this constructed value; and HTA, in turn, shapes clinical practice through reimbursement, service availability and opposable guidance. Modern HTA increasingly incorporates patient involvement, patient-reported outcomes, discrete choice experiments, deliberative processes and multi-criteria decision analysis, but these remain structurally secondary to population-level quantitative evidence. Conclusion. Positivism and constructivism are complementary rather than opposed. A more pluralist HTA — one that makes preference heterogeneity, experienced utility and the underlying facts, norms and values explicit — would be more, not less, evidence-based, and would widen the room clinicians have to practise person-centred care. The vignettes are pedagogical illustrations, not empirical evidence.