Come valutare i risultati di uno studio farmacoeconomico?

Summary

Can a National Health Service afford to provide its patients with an innovative, expensive technology, face to competing alternatives? Trying to answer this question, the economic evaluation of a new medical technology aims at improving the allocation of scarce resources for health care use.

Evaluations are performed using analytical tools, such as Incremental Cost Effectiveness Ratios (ICERs), where the additional cost due to a new technology is related to its additional benefits (typically: years of life gained, maybe adjusted for utility). But once an ICER is quantified, it has to be compared with a meaningful threshold value, in order to know whether it is acceptable or not on financial grounds.

Thresholds are chiefly expressed as ICERs, calculated for technologies already approved by regulatory bodies and about which consensus is widespread. They are generally intended as absolute values (i.e. that can be applied in different environments) and most references are made to the Anglo-Saxon experience (United Kingdom, Australia, USA etc.). But relative thresholds are also suggested in the literature (such as indicators based on a country’s GDP), allowing evaluations which are closer to the features of specific economic/health systems. The classic tool for the potential use of threshold values by policy makers are League Tables (LTs), that is lists of technologies ranked by cost-effectiveness. LTs can be used for a twofold purpose: one (in the theory) would be to efficiently allocate a given amount of resources to different programmes; the other (in practice) is to provide benchmarks for the ICERs of new technologies on trial for adoption. LTs have several limitations, due to non negligible differences in their sources, to time driven changes in their marginality criteria, and several other reasons; so, they should be considered a work in progress rather than a finished one.

It should be stressed that compliance with a threshold value is a necessary but not sufficient condition for a new technology to be accepted. The actual availability of an additional budget is, in fact, a pre-requisite. Of course, the determination of such budget is beyond the responsibility of regulatory bodies; but the underlying problem is often ignored in the ongoing debate.

Last but not least, an original procedure is presented providing an estimate of how much some European countries have (each) de facto spent in order to produce an additional year of life — which could be viewed as one more kind of threshold value. For doing so, data published by OECD (PYLLs, potential years of life lost) were utilised.