The usefulness of ratios for allocation decisions: The case of stroke

Economic evaluation is becoming increasingly important in the field of stro ke as well. The results of economic evaluation can be expressed in cost per quality-adjusted life years (QALY) gained, which enables policy makers to compare the relative efficiency of different interventions regarding differ ent diseases. Although using the concept of QALY is preferable from a theor etical point of view, in medical practice more often cost-effectiveness ana lysis (CEA), and not cost-utility analysis, is applied for practical reason s. One of the main limitations of CEA is that the results may be compared o nly with results of other CEAs, using the same effect parameter. The calcul ation of cost-effectiveness ratios (CERs) in many cases is misleading for r esource allocation. Effects should be expressed in interval or ratio scales in order to calculate CERs, which is rarely the case. The calculation of a CER in a CEA should only be performed if, and only if, the investigator is convinced that there is a constant relation between the specific effect pa rameter and the ultimate gain in health. Copyright (C) 2000 S. Karger AG, Basel.