Most phase III clinical trials today are explanatory. Because explanatory, or efficacy, trials test hypotheses under “ideal” conditions, they are not well suited to providing guidance on decisions made in most clinical care contexts. Pragmatic trials, which test hypotheses under “usual” conditions, are often better suited to this task. Yet, pragmatic, or effectiveness, trials are infrequently carried out. This mismatch between the design of clinical trials and the needs of health care professionals is frustrating for everyone involved, and explains some (...) of the challenges inherent in attempts to enhance knowledge translation and encourage evidence-based practice. The situation is more than simply frustrating, however; it is potentially unethical. Clinical trials must be socially valuable in order to (1) warrant the risks they impose on human research subjects and (2) fairly and efficiently assess new clinical interventions. Most bioethicists would agree that trials that have no social value, for instance, because their results do not have the potential to advance clinical care, should not be performed. What is less widely appreciated is that given limited research resources, trials that are more socially valuable should be preferred to trials that are less socially valuable when all else is equal. With respect to clinical trial design, I argue that while explanatory trials often have some social value, many have less social value than their pragmatic counterparts. On the basis of this general ethical assessment, I provide a preliminary defense of the position that clinical researchers should aim to conduct pragmatic trials, that is, that researchers face a burden of justification related to any idealizing elements added to trial designs. (shrink)

The explanatory/pragmatic-trial distinction enjoys a burgeoning philosophical and medical literature and a significant contingent of support among philosophers and healthcare stakeholders as an important way to assess the design and results of randomized controlled trials. A major motivation has been the need to provide relevant, generalizable data to drive healthcare decisions. While talk of pragmatic and explanatory trials could be seen as convenient shorthand, the distinction can also be seen as harboring deeper issues related to inferential strategies used to evaluate (...) causal claims regarding medical treatments. A comprehensive, critical analysis of the distinction and underlying epistemological framework upon which the distinction is based, particularly with respect to treatment effectiveness, has yet to be forthcoming. I provide this, analyzing the distinction’s relationship to generalizability and cognate distinctions between ideal conditions and real-world practice, internal and external validity, and efficacy and effectiveness. I also analyze recent philosophical work that relies on the explanatory/pragmatic-trial distinction and that advocates for more pragmatic trials. I conclude that as an organizing principle for trial-design decisions and trial evaluation, the explanatory/pragmatic-trial distinction is conceptually problematic and not as useful as its proponents seem to think. Since some pragmatic-trial features can be inimical to establishing treatment effectiveness, pragmatic-trial features should not be conflated with pragmatic trials’ avowed goals. If the distinction is to be useful, it and some associated concepts, including generalizability, should be reformulated, lest they continue to underlie a medical epistemology that could contribute to methodologically flawed and potentially unethical advice for the design and interpretation of trials. (shrink)

Ethical challenges to certain aspects of research on human subjects are not uncommon; examples include challenges to first-in-human trials (Chapman in J Clin Res Bioethics 2(4):1–8, 2011), certain placebo controlled trials (Anderson in J Med Philos 31:65–81, 2006; Anderson and Kimmelman in Kennedy Inst Ethics J 20(1):75–98, 2010) and “sham” surgery (Macklin in N Engl J Med 341:992–996, 1999). To date, however, there are few challenges to research when the subjects are competent and the research is more than minimal risk (...) with no promise of direct benefit. The principal reason given for allowing research that is more than minimal risk without benefit is that we should respect the autonomy of competent subjects. I argue that though the moral intuitions informing respect for autonomy are sound, there is another set of intuitions regarding what we take to be just treatment of another when one agent knowingly causes or allows suffering on another agent. I argue that concerns generated by commutative justice serve as limitations on permissible research. I highlight our intuitions informing this notion of justice by appealing to work done on theodicy; what counts as a morally sufficient reason for God to allow suffering in humans is applicable also to the researcher-subject relationship. I conclude that all human subjects who are exposed to more than minimal risk research should enjoy the same actual protections (e.g., subpart D) as those given subjects who cannot consent. (shrink)

The Belmont Report’s distinction between research and the practice of accepted therapy has led various authors to suggest that these purportedly distinct activities should be governed by different ethical principles. We consider some of the ethical consequences of attempts to separate the two and conclude that separation fails along ontological, ethical, and epistemological dimensions. Clinical practice and clinical research, as with yin and yang, can be thought of as complementary forces interacting to form a dynamic system in which the whole (...) exceeds the sum of its parts. Just as effective clinical practice cannot exist without clinical research, meaningful clinical research requires the context of clinical practice. We defend this thesis by triangulation, that is, by outlining how multiple investigators have reached this conclusion on the basis of varied theoretical and applied approaches. More confidence can be placed in a result if different methods/viewpoints have led to that result. (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)

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)

The concept of clinical equipoise restricts the use of placebo controls in clinical trials when there already exists a proven effective treatment. Several critics of clinical equipoise have put forward alleged counter-examples to this restriction—describing instances of ethical placebo-controlled trials that apparently violate clinical equipoise. In this essay, we respond to these examples and show that clinical equipoise is not as restrictive of placebos as these authors assume. We argue that a subtler appreciation for clinical equipoise—in particular the distinction between (...) de facto and de jure interpretations of the concept—allows the concept to explain when and why a placebo control may be necessary to answer a question of clinical importance. (shrink)

John Worrall and Nancy Cartwright have both argued that randomized controlled trials are “testing the wrong theory.” They claim that RCTs are designed to test inferences about the causal relationships in the study population, but this does not guarantee a justified inference about the causal relationships in the more diverse population in clinical practice. In this article I argue that the epistemology of theory testing in trials is more complicated than either Worrall’s or Cartwright’s accounts suggest. I illustrate this more (...) complex theoretical structure with case studies in medical theory testing from Alzheimer’s research and anticancer drugs in personalized medicine. (shrink)

What makes a high-quality biomarker experiment? The success of personalized medicine hinges on the answer to this question. In this paper, I argue that judgment about the quality of biomarker experiments is mediated by the problem of theoretical underdetermination. That is, the network of biological and pathophysiological theories motivating a biomarker experiment is sufficiently complicated that it often frustrates valid interpretation of the experimental results. Drawing on a case-study in biomarker diagnostic development from neurooncology, I argue that this problem of (...) underdetermination can be overcome with greater coordination across the biomarker research trajectory. I then sketch an account for how coordination across a research trajectory can be evaluated. I ultimate conclude that what makes a high-quality biomarker experiment must be judged by the epistemic contribution it makes to this coordinated research effort. (shrink)

It has been almost 20 years since the field of bioethics was galvanized by a controversial series of multinational AZT trials employing placebo controls on pregnant HIV-positive women in the developing world even though a standard of care existed in the sponsor countries. The trove of ethical investigations that followed was thoughtful and challenging, yet an important and problematic methodological assumption was left unexplored. In this article, I revisit the famous “double standard of care” case study in order to offer (...) novel consideration of the placebo orthodoxy that underlies much of the ethical debate. This majority view found in medical research is that placebo-controlled trials are methodologically superior to comparative trials that use active controls. I challenge this orthodoxy and argue that lives were unnecessarily lost in these trials as a result. Furthermore, current HIV research on vaccines and microbicides is now poised to repeat the error of subscribing to the placebo orthodoxy. (shrink)

What makes a high-quality biomarker experiment? The success of personalized medicine hinges on the answer to this question. Unfortunately, as many commentators have now emphasized, the quality of most biomarker experiments to date has been quite low. Although the technical side of this problem has received considerable attention, the philosophical issues remain largely unexplored. In this paper, I argue that understanding what constitutes a high-quality biomarker experiment requires some fundamental shifts in how we think about the epistemology, ontology, and methodology (...) of clinical translation. (shrink)

In robustness analysis, hypotheses are supported to the extent that a result proves robust, and a result is robust to the extent that we detect it in diverse ways. But what precise sense of diversity is at work here? In this paper, I show that the formal explications of evidential diversity most often appealed to in work on robustness – which all draw in one way or another on probabilistic independence – fail to shed light on the notion of diversity (...) relevant to robustness analysis. I close by briefly outlining a promising alternative approach inspired by Horwich’s (1982) eliminative account of evidential diversity. (shrink)

Hierarchies of evidence are an important and influential tool for appraising evidence in medicine. In recent years, hierarchies have been formally adopted by organizations including the Cochrane Collaboration [1], NICE [2,3], the WHO [4], the US Preventive Services Task Force [5], and the Australian NHMRC [6,7]. The development of such hierarchies has been regarded as a central part of Evidence-Based Medicine, a movement within healthcare which prioritises the use of epidemiological evidence such as that provided by Randomised Controlled Trials. Philosophical (...) work on the methodology of medicine has so far mostly focused on claims about the superiority of RCTs, and hence has largely neglected the questions of what hierarchies are, what assumptions they require, and how they affect clinical practice. This thesis shows that there is great variation in the hierarchies defended and in the interpretations they are, and can be, given. The interpretative assumptions made in using hierarchies are crucial to the content and defensibility of the underlying philosophical commitments concerning evidence and medical practice. Once this variation is been identified, it becomes clear that the little philosophical work that has been done so far affects only some hierarchies, under some interpretations. Modest interpretations offered by La Caze [11], conditional hierarchies like GRADE [12-14], and heuristic approaches such as that defended by Howick et al. [15,16] all survive previous philosophical criticism. This thesis extends previous criticisms by arguing that modest interpretations are so weak as to be unhelpful for clinical practice; that GRADE and similar conditional models omit clinically relevant information, such as information about variation in treatments’ effects and the causes of different responses to therapy; and that heuristic approaches lack the necessary empirical support. The conclusion is that hierarchies in general embed untenable philosophical assumptions: principally that information about average treatment effects backed by high-quality evidence can justify strong recommendations, and that the impact of evidence from individual studies can and should be appraised in isolation. Hierarchies are a poor basis for the application of evidence in clinical practice. The Evidence-Based Medicine movement should move beyond them and explore alternative tools for appraising the overall evidence for therapeutic claims. (shrink)

In the first half of this dissertation, I develop a heuristic methodology for analyzing scientific solutions to the problem of underdetermination. Heuristics are rough-and-ready procedures used by scientists to construct models, design experiments, interpret evidence, etc. But as powerful as they are, heuristics are also error-prone. Therefore, I argue that they key to prudently using a heuristic is the articulation of meta-heuristics---guidelines to the kinds of problems for which a heuristic is well- or ill-suited. Given that heuristics will introduce certain (...) errors into our scientific investigations, I emphasize the importance of a particular category of meta-heuristics involving the search for robust evidence. Robustness is understood to be the epistemic virtue bestowed by agreement amongst multiple modes of determination. The more modes we have at our disposal, and the more these confirm the same result, the more confident can we be that a result is not a mere artifact of some heuristic simplification. Through an analysis of case-studies in the philosophy of biology and clinical trials, I develop a principled method for modeling and evaluating heuristics and robustness claims in a qualitative problem space. The second half of the dissertation deploys the heuristic methodology to address ethical and epistemological issues in the science of clinical trials. To that end, I develop a network model for the problem space of clinical research, capable of representing the various kinds of experiments, epistemic relationships, and ethical justifications intrinsic to the domain. I then apply this model to ongoing research with the antibacterial agent, moxifloxacin, for the treatment of tuberculosis, tracking its development from initially successful and promising in vitro and animal studies to its disappointing and discordant performance across five human efficacy trials. Given this failure to find a robust result with moxifloxacin across animal and human studies, what should researchers now do? While my final analysis of this case does not definitively answer that question, I demonstrate how my methodology, unlike a statistical meta-analysis, helps to clarify the directions for further research. (shrink)