The Morality of Placebo-Controlled Trials
by David Zhang on February 10, 2015 - 5:13pm
The Morality of Placebo-Controlled Trials (PCTs)
After a new drug or treatment is developed and tested on animals, its efficiency must be tested through trials on humans. To be able to evaluate what effects are caused by the medicament, only a part of the patients receives the treatment, allowing the formation of a control group. To allow reliable comparison, the patients from the control group and the patients from the group that actually received the drug must ideally differ solely by one trait, the presence or absence of the drug in their organism. Therefore, the true effect of a drug can only be determined if the patients that received it and the patients that did not are both provided with the same amount of information (since psychological expectations often influence recovery), that is, a good scientific trial requires that no one knows who has received a true drug and who got a placebo. This allows to get rid of the placebo effect.
From the fact that the safe development of new drugs requires placebo-controlled trials (or at least some kind of control group that is not provided with the medication, but that comes to the same thing) arises an ethical dilemma: Is it moral to give a sick patient a placebo in the context of a clinical drug testing although there is a drug (the one that is tested) that is available and has a much higher probability of yielding significant results?
I believe that the best solution to this moral dilemma is obtained when using a teleological framework, or more precisely, a utilitarian one. Indeed, for a disease that would only cause trivial symptoms such as headaches or fatigue, the option of the PCT would seem ethical; however, for severe diseases (such as the recent ebola epidemic), the almost-consensual option seems to be not to give a dummy shot to a dying man. It thus feels natural that the consequences of the different options (which are: giving a placebo or not) must be taken into consideration when searching for the moral thing to do because of the significant variance between diseases. Now, we need a way to evaluate the consequences of each option so that we can determine for which diseases we can use PCTs, or in other words, the point where the tolerance for placebo shifts from no to yes. Utilitarianism provides us with a way to evaluate the consequences and thus the morality of the options.
Let us take happiness as the summum bonum for our society. Therefore, the option we choose in a particular situation must be the one that leads us to the best consequence, that is, the higher degree of happiness in the society as a whole. In the disease-centered situations that interest us, the degree of happiness is dependent on health (the scientific progress can be translated as future health), and so, health is what we should seek to maximize.
Let us examine the extreme cases. If we use PCTs when the disease is very deadly, then health is not maximized since we can consider the lives of those to whom we administered a placebo as wasted: we did not really (from an ethical rather than purely scientific perspective) need a placebo to evaluate whether or not the drug was functional (since the psychological effects of a sugar pill on a deadly illness are negligible). In the opposite case, if we never used PCTs on mild diseases (i.e. diseases that could almost be overcome with placebos), we would not at all be able to determine the efficiency of a drug; and thus, we would not be maximizing future health.
Hence, from a teleological ethical perspective, the theoretical moral rule that regulates the use of PCTs would be somewhere between these two extremes (never and always using PCTs). To be ethical, that is, to maximize health for the society as a whole, placebos should only be used in clinical drug testing in the case of a disease whose severity is below the point where the possible effects of a placebo are scientifically negligible compared to the severity of the illness. That way, PCTs are used strategically to maximize happiness since they help the development of science (future health) while not causing sacrifices of human lives in the short term.
How this rule is applied in practice or what this turning point actually corresponds to is difficult to define. Although it probably implies a huge margin of uncertainty, I believe that it is feasible to establish a certain standard for this turning point by comparing the maximal potential effect of placebos on recoveries (which could be estimated through studies on placebos) to the expected effects of the actual drug that is tested (which comes from animal trials). This comparison (which basically corresponds to “clinical equipoise” (Wikipedia)) could serve as an indicator of how much of a sacrifice the use of a PCT in a particular situation would be, which, coupled to an estimation of the evolution of the disease (which is obviously subject to error) should be enough to allow a calculation of how much harm would be done in both options (if PCTs are used or not).
Nonetheless, despite the practical issues, this rule on the use of PCTs remains the ethical way (from a utilitarian perspective) to solve the dilemma.
"Clinical equipoise." Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 21 January 2015. Web. 10 Feb. 2015.