Opportunity cost, cost-effectiveness threshold, technological displacement and net population health loss in the process of incorporation and diffusion of technologies in national health systems

Abstract

This article makes a narrative review of the concepts of cost-effectiveness threshold and opportunity cost of national health systems, focusing on public systems, in view of the reality of the budget constraint common to these systems – and particularly severe in the case of SUS_ and the process of incorporation and diffusion of technologies. The fundamental economic concept of opportunity cost, applied to health systems, in the case of the decision on the incorporation of technologies, is the health that would have been obtained by services no longer offered in order to accommodate the costs of the new technology. The opportunity cost of a health system informs the marginal health productivity of that system, how efficiently it operates: what extra amount of financial resources—measured in currency or in GDP pc—is needed for that system to produce a given extra health benefit _ measured in QALY or DALY. The estimation of the opportunity cost of a national system is important as evidence necessary to define the cost-effectiveness threshold of this system. Studies that developed methodologies to estimate the opportunity cost of national health systems and their respective findings, including for Brazil, are presented; problems related to the endogeneity of the relationship between expenditures and health outcomes and the definition of instrumental variables are mentioned. The article explores the concept of technological displacement to address the significance for the health system, in terms of health productivity, of the incorporation of technologies with an incremental cost-effectiveness ratio (ICER) higher than the opportunity cost of the system. Finally, it presents the concept and estimates made of the net loss of health for the population, resulting from processes of technological displacement. The reviewed studies indicate that the threshold to be used for the incorporation and diffusion of technologies in the SUS should be significantly below 1 GDP pc per QALY.