The last two decades have witnessed intense debate over the ethical legitimacy of placebo controlled trials. Most of the arguments for and against the use of PCTs turn on one of the following issues: the compatibility of the obligations of clinicians and researchers with PCTs, the scientific merit of PCTs, and the influence of patients' and subjects' perceptions, ability to consent, expectations, and rights on the permissibility of PCTs. I introduce each of these categories and assess the principal (...) arguments in each group. I argue that, although some of the arguments against PCTs have limitations, they do inform the debate in significant ways by pointing to important constraints on PCTs. Those concerning patients' and subjects' perceptions, capacity to consent, expectations, and rights are particularly instructive. They do not, for the most part, sustain an absolute prohibition of PCTs, but they do suggest types of PCTs that are inappropriate and they indicate issues that must be addressed when PCTs are conducted. I argue that we should look to the reasonableness and permissibility of informed refusals of care to evaluate the extent to which a trial is a legitimate PCT ; to determine which potential subjects should be considered eligible to enroll in a PCT ; and to inform the language that should be used in describing the study as part of the informed consent process. (shrink)

The principle of clinical equipoise requires that, aside from certain exceptional cases, second generation treatments ought to be tested against standard therapy. In violation of this principle, placebo-controlled trials (PCTs) continue to be used extensively in the development and licensure of second-generation treatments. This practice is typically justified by appeal to methodological arguments that purport to demonstrate that active-controlled trials (ACTs) are methodologically flawed. Foremost among these arguments is the so called assay sensitivity argument. In this paper, (...) I take a closer look at this argument. Following Duhem, I argue that all trials, placebo-controlled or not, rely on external information for their meaningful interpretation. Pending non-circular empirical evidence that we can trust the findings of PCTs to a greater degree than the findings of ACTs, I conclude that the assay sensitivity argument fails to demonstrate that placebo-controlled trials are preferable, methodologically or otherwise, to active-controlled trials. Contrary to the intentions of its authors, the fundamental lesson taught by the assay sensitivity argument is Duhemian: the validity of all clinical trials depends on external information. (shrink)

A resilient issue in research ethics is whether and when a placebo-controlled trial is justified if it deprives research subjects of a recognized treatment. The clinicians' moral duty to provide the best available care seems to require the use of ‘active’ controlled trials that use an established treatment as a control whenever such a therapy is available. In another regard, ACTs are supposedly methodologically inferior to PCTs. Hence, the moral duty of the clinical researcher to use (...) the best methods will favor PCTs. In this target article, I analyze the three reasons for believing that ACTs are inferior to PCTs namely: 1) ACTs lack ‘assay sensitivity’; 2) ACTs do not measure absolute effect size; and 3) ACTs require more participants; and I contend that none are acceptable. Consequently the tension between clinical and research ethics dissolves: the moral duty of the clinician to avoid PCTs is unopposed by methodological considerations. (shrink)

According to Howick (2009a), the three main reasons for believing that placebo-controlled trials (PCTs) are methodologically superior to active-controlled trials (ACTs)—sensitivity, absolute effect...

A resilient issue in research ethics is whether and when a placebo-controlled trial is justified if it deprives research subjects of a recognized treatment. The clinicians' moral duty to provide the best available care seems to require the use of ‘active’ controlled trials that use an established treatment as a control whenever such a therapy is available. In another regard, ACTs are supposedly methodologically inferior to PCTs. Hence, the moral duty of the clinical researcher to use (...) the best methods will favor PCTs. In this target article, I analyze the three reasons for believing that ACTs are inferior to PCTs namely: 1) ACTs lack ‘assay sensitivity’; 2) ACTs do not measure absolute effect size; and 3) ACTs require more participants; and I contend that none are acceptable. Consequently the tension between clinical and research ethics dissolves: the moral duty of the clinician to avoid PCTs is unopposed by methodological considerations. (shrink)

Part of the National Placebo Initiative in Canada included public consultations, based on the belief that the views of the public should inform Canadian policy development on what constitutes appropriate placebo use. Public consultations took place nationally in 2003. A deliberative dialogue approach was used, or a structured discussion format designed to facilitate the consideration of complex issues and build consensus. The placebo debate was characterized as having 3 distinct approaches and each were explored. The first approach (...) “Maximize Patient Protection” identified the need for experts to determine appropriate placebo use and that placebos should only be allowed under very restricted conditions. The second approach “Maximize Medical Knowledge” identified that placebos give essential information about the safety and efficacy of new drugs, and are appropriate when the rights, safety and well-being of research participants are ensured. The third approach “Maximize Patient Autonomy” identified that the current system of regulating placebo use is paternalistic and that patients should be able to define what is in their best interests and have more leeway to determine for themselves if they wish to participate in a placebo-controlled trial. Advantages and disadvantages of each approach were considered and feedback on what constitutes appropriate placebo use was sought. The major findings were that: PCTs were considered a valuable and acceptable part of advancing medical knowledge; research using placebos must be valid and justifiable; a patient-centred approach needs to be fostered; patient autonomy (choice) should be a first consideration and take clear precedence in trials of low to medium risk; patient protection (or health) may need to “trump” patient autonomy at higher levels of risk and/or patient vulnerability; placebos are not a violation of the duty of care as duty of care is best met by identifying a choice for patients, whenever a choice is available. These consultations clearly were not designed to produce conclusive evidence, but rather to provide some useful insights into what the public may think about placebo use; additional studies are indicated. (shrink)