Generic and therapeutic substitution: ethics meets health economics

Abstract

To the Editor: In their commentary on the ethical aspects of generic and therapeutic substitution, AlAmeri et al. [1] argued that the health economic rationale for promoting substitution, i.e. the creation of cost savings to the health care system, may be harmful to patients and, thus, that substitution is unethical. They then go on to state that the debate on whether or not to substitute must be exclusively informed by the individual patient’s clinical interests and that substitution driven by economic interests is not compatible with patient-centered medicine. In putting these arguments forward, the authors misinterpret the ethical implications of a health economic framework by focusing on the individual patient’s perspective to the detriment of the societal perspective. The ethical dimension underpinning health economics is that a society wishes to maximise population health subject to a budget constraint. This idea is reflected in the term ‘health economics’, which consists of two words, with ‘health’ coming first and ‘economics’ coming second. Given that society can fund some, but not all available health technologies in an era of limited resources, society allocates the finite budget to those health technologies that maximize population health. Health economic theory has demonstrated that, if health technologies are ranked according to their cost-effectiveness, health can be maximised by funding health technologies in decreasing order of cost-effectiveness until the budget is exhausted. In this respect, substitution can increase the cost-effectiveness of existing pharmacotherapy and improve population health, as shown for example by the increasing cost-effectiveness of all statin therapies in Spain following the introduction of generic statins [2]. AlAmeri et al. [1] agreed that if clinical studies have demonstrated an equal safety and effectiveness profile of a generic medicine and the reference medicine, then substitution can be undertaken and the least expensive medicine needs to be chosen. However, it may be ethical to substitute the reference with a generic medicine even if the generic medicine is less effective than the reference medicine. Health economics shows that substitution can be costeffective if the savings in total health care costs are large enough to offset the reduction in effectiveness. If substitution is undertaken in this scenario, society is able to free resources and invest those in more cost-effective health technologies, thereby generating an overall increase in population health, even when this leads to a decrease in the individual patient’s clinical outcomes. Conversely, prescription of the more expensive reference medicine would improve the individual patient’s clinical outcomes, but would be accompanied by a decrease in population health that is larger than the improvement in the patient’s outcomes. In this respect, health economics chooses the clinical interests of society as a whole in order to be ethical rather than those of the individual patient or of a specific patient group. When discussing the impact of substitution on patient’s clinical interests, AlAmeri et al. [1] considered the potential negative impact of substitution on patient satisfaction and on adherence to treatment, but did not take account of the possible positive impact. For instance, substitution may sustain the affordability of health care and may enable a larger number of patients to gain access to health care. In The author holds the EGA chair ‘European policy towards generic medicines’.