Nonsense on Stilts - Part 1: The ICER 2020-2023 Value Assessment Framework for Constructing Imaginary Worlds.

Abstract

Previous commentaries in the Formulary Evaluation section of INNOVATIONS in Pharmacy have pointed to the lack of credibility in modeled claims for cost-effectiveness and associated recommendations for pricing and access by the Institute for Clinical and Economic Review (ICER). The principal objection to ICER reports has been that their modeled claims fail the standards of normal science: they are best seen as pseudoscience. The purpose of this latest commentary is to provide a critique of the recently released ICER 2020 Value Assessment Framework (VAF). Although ICER has taken upon itself the pole position in health technology assessments and recommendations for product pricing in the US health care system, the incremental, lifetime cost-per-QALY modeling methodology should not be taken seriously. The creation of imaginary modeled worlds, built entirely from assumption, fails the demarcation test between science and pseudoscience. The ICER evidence reports are best seen as the health technology assessment equivalent of 'intelligent design' in counterpoint to 'natural selection'. It is surprising, therefore, that health care decision makers should take ICER's recommendations seriously as providing 'approximate information' for formulary decision making. What is not appreciated is that the claims made by ICER lack credibility, are impossible to evaluate and lack the ability to be replicated across treatment settings. Indeed, the models presented under the guise of a 'state of the art' value assessment were never intended to support evaluable claims. We have no idea and will never know if they are right or if they are wrong. ICER's position becomes even more untenable once the models presented are assessed in detail. Without in any way supporting the ICER methodology, it is worth noting that all too often ICER's claims for incremental QALYs in specific models are based upon what appears to be, from the limited evidence presented, a casual and ad hoc assemblage of utility scores from diverse constructs. This is a critical weakness given the role attributed by ICER to the modeled cost-per-QALY claims as central to ICERs imaginary value assessment. ICER also overlooks the fact that the utility scores it captures from the literature to populate its imaginary reference case world lack objectivity. They are ordinal rather than interval measures. To apply these manifest scores to time spent in a disease stage and then aggregate these over different disease stages is nonsensical. The critical issue is one of instrument development. The case made here is for the application of Rasch Measurement Theory (RMT) to construct a unidimensional instrument with interval properties, in this case from the needs fulfillment construct of quality of life (QoL). Unless an instrument meets RMT standards in its development, the logic of Rasch modeling to achieve fundamental measurement standards means that other scales are, by definition, ordinal. It is absurd to 'assume' they are interval. RMT is designed to create instruments to evaluate change and test hypotheses. In the absence of instruments that have RMT properties, the cost-per-QALY reference case modelling meme collapses. It is an analytical dead end. If we are to support a meaningful scientific program to discover new facts to support health care delivery and improve the lives of patients, caregivers and their families, then ICER should be put to one side.