MEASUREMENT: US & UK

ARITHMETIC BEFORE MEASUREMENT

Large language model interrogations of HTA knowledge bases provide a unique opportunity to
examine how measurement concepts are represented within the institutions that have played the
leading role in the development of modern health technology assessment. Across agencies,
academic research centres, professional organizations, journals and educational programs in the
United States and United Kingdom, these interrogations allow a systematic evaluation of the
place of representational measurement within contemporary HTA.

The results reveal a remarkably consistent pattern. Foundational propositions concerning
representational measurement, ratio measurement, dimensional homogeneity and the principle
that measurement must precede arithmetic receive relatively weak endorsement. At the same
time, propositions supporting utilities, QALYs, reference-case simulation models and cost-
effectiveness claims receive strong endorsement. These findings suggest that measurement
considerations occupy a limited role within the dominant HTA framework despite their
importance to the construction and interpretation of quantitative claims.

This pattern is important because it highlights the relationship between measurement and therapy
assessment. Every quantitative discipline depends upon lawful measurement before arithmetic
can be undertaken. The interrogations therefore provide a lens through which to examine
whether current HTA practice recognizes the requirements imposed by scales of measurement
and the axioms of representational measurement. Particular attention is given to the distinction
between manifest and latent attributes, the role of ratio measurement and the contribution of
Rasch measurement to the assessment of subjective outcomes.

The purpose of this section is to present the evidence from the United States and United
Kingdom and to consider its implications for the future development of HTA. The central
question is straightforward: to what extent do current HTA knowledge bases recognize the
measurement standards required for credible, evaluable and replicable claims regarding therapy
impact? The interrogations provide a basis for addressing that question and for considering how
measurement may contribute to the continuing evolution of HTA as a scientific discipline.

LEADING US ACADEMIC RESEARCH CENTERS

Interrogations of leading US academic research centers reveal the same pattern observed across
HTA agencies and educational programs. Foundational principles of representational
measurement receive weak endorsement, while utilities, QALYs, reference-case simulation
models and cost-effectiveness claims receive strong support. Rasch measurement is effectively
absent, despite its central role in the measurement of latent attributes. The result is a shared
pattern of measurement inversion in which arithmetic precedes measurement,

LEADING US ACADEMIC JOURNALS

Interrogations of leading US journals publishing health technology assessment and pharmacoeconomic
research reveal a remarkably consistent pattern in the treatment of measurement concepts.
Propositions associated with representational measurement, ratio measurement, dimensional
homogeneity and the principle that measurement must precede arithmetic receive relatively weak
endorsement, while utilities, QALYs, reference-case simulation models and cost-effectiveness claims
receive strong support. Rasch measurement is largely absent despite its importance in the assessment
of latent attributes. These findings suggest that the dominant journal literature is primarily oriented
toward simulation-based evaluation and utility-based outcomes rather than the requirements imposed
by the scales of measurement and the axioms of representational measurement. The result is a
reproducible pattern of measurement inversion that continues to shape HTA research, publication and
professional practice.