The question of what monetary value should be assigned to consumed resources, that is to say the choice of the unit cost, is a major consideration in terms of impact on the cost analysis results. To date, no agreement has been reached regarding this methodological question. The choices made by methodologists and the subsequent impact on the results of the analysis are only rarely put forward. This work addresses the theoretical framework of health strategy evaluations that can be carried out either in the normative framework of the conventional economic approach of well-being, referred to as welfarist, or in that of an approach referred to as extra-welfarist. It also provides elements that help clarify the choice of the hospital unit costs used to calculate the cost of health strategies, so as to reconcile the use of such studies and improve their comparability. What is preferable, opting for specific per hospital unit costs or applying a standard unit cost to all facilities? How should a standard cost be calculated? Is it appropriate to calculate an average of the unit costs, as recommended by certain guidelines? The advantages and the limitations of the various modes of assessing hospital resources in the setting of multicentric trials are discussed.