Jonathan Fuller

The Risk GP Model: The standard model of prediction in medicine

With the ascent of modern epidemiology in the Twentieth Century came a new standard model of prediction in public health and clinical medicine. In this article, we describe the structure of the model. The standard model uses epidemiological measures-most commonly, risk measures-to predict outcomes (prognosis) and effect sizes (treatment) in a patient population that can then be transformed into probabilities for individual patients. In the first step, a risk measure in a study population is generalized or extrapolated to a target population. In the second step, the risk measure is particularized or transformed to yield probabilistic information relevant to a patient from the target population. Hence, we call the approach the Risk Generalization-Particularization (Risk GP) Model. There are serious problems at both stages, especially with the extent to which the required assumptions will hold and the extent to which we have evidence for the assumptions. Given that there are other models of prediction that use different assumptions, we should not inflexibly commit ourselves to one standard model. Instead, model pluralism should be standard in medical prediction.

Rhetoric and argumentation: how clinical practice guidelines think

Introduction Clinical practice guidelines (CPGs) are an important source of justification for clinical decisions in modern evidence-based practice. Yet, we have given little attention to how they argue their evidence. In particular, how do CPGs argue for treatment with long-term medications that are increasingly prescribed to older patients? Approach and rationale I selected six disease-specific guidelines recommending treatment with five of the medication classes most commonly prescribed for seniors in Ontario, Canada. I considered the stated aims of these CPGs and the techniques employed towards those aims. Finally, I reconstructed and logically analysed the arguments supporting recommendations for pharmacotherapy. Analysis The primary function of CPGs is rhetorical, or persuasive, and their means of persuasion include both a display of their credibility and their argumentation. Arguments supporting pharmacotherapy recommendations for the target population follow a common inductive pattern: statistical generalization from randomized controlled trial (RCT) and meta-analysis evidence. Two of the CPGs also argue their treatment recommendations for older patients in this style, while three fail to justify pharmacotherapy specifically for the older population. Discussion The arguments analysed lack the auxiliary assumptions that would warrant making a generalization about the clinical effectiveness of medications for the older population. Guidelines reason using simple induction, while ignoring important inferential gaps. Future guidelines should aspire to be well-reasoned rather than simply evidence-based; argue from a plurality of evidence; be wary of hasty inductions; appropriately limit the scope of their recommendations; and avoid making law-like, prescriptive generalizations.INTRODUCTION Clinical practice guidelines (CPGs) are an important source of justification for clinical decisions in modern evidence-based practice. Yet, we have given little attention to how they argue their evidence. In particular, how do CPGs argue for treatment with long-term medications that are increasingly prescribed to older patients? APPROACH AND RATIONALE: I selected six disease-specific guidelines recommending treatment with five of the medication classes most commonly prescribed for seniors in Ontario, Canada. I considered the stated aims of these CPGs and the techniques employed towards those aims. Finally, I reconstructed and logically analysed the arguments supporting recommendations for pharmacotherapy. ANALYSIS The primary function of CPGs is rhetorical, or persuasive, and their means of persuasion include both a display of their credibility and their argumentation. Arguments supporting pharmacotherapy recommendations for the target population follow a common inductive pattern: statistical generalization from randomized controlled trial (RCT) and meta-analysis evidence. Two of the CPGs also argue their treatment recommendations for older patients in this style, while three fail to justify pharmacotherapy specifically for the older population. DISCUSSION The arguments analysed lack the auxiliary assumptions that would warrant making a generalization about the clinical effectiveness of medications for the older population. Guidelines reason using simple induction, while ignoring important inferential gaps. Future guidelines should aspire to be well-reasoned rather than simply evidence-based; argue from a plurality of evidence; be wary of hasty inductions; appropriately limit the scope of their recommendations; and avoid making law-like, prescriptive generalizations.

Rationality and the generalization of randomized controlled trial evidence

The randomized controlled trial (RCT) is the gold standard of evidence because it has the highest internal validity; that is, its design is better than any other at preventing various sources of systematic bias from confounding our judgement. The preceding assertion has been amply rehearsed. It is precisely what is meant by the RCT’s placement above all other population study designs in the hierarchy of evidence for prevention and treatment decisions. The hierarchy has been the target of a battery of criticisms over the past two decades [1], yet it lives on in the most recent edition of the Users’ Guides to the Medical Literature: Essentials of Evidence-Based Clinical Practice [2], and the randomized trial still rules. Recurrent among critiques of the RCT are concerns over its external validity [3–13]. The common thread to these arguments is that trials map poorly onto the reality of clinical medicine; the trial participants are not representative of patients routinely encountered by clinicians, and the ideal and pristine trial conditions are too dissimilar from the concrete and messy world of clinical practice. Concerns about the representativeness of trial populations are neither exaggerated nor trivial. A systematic review of 283 RCTs published in major medical journals found that 81.3% of trials excluded patients due to common co-morbidities, 38.5% due to older age and 54.1% due to concurrent use of commonly prescribed

Renaissance or reformation for evidence based medicine

We welcome the new directions for evidence based medicine sketched out by Greenhalgh and colleagues on behalf of the Evidence Based Medicine Renaissance Group.1 However, we wonder whether their movement will represent a renaissance—a sweeping intellectual revival for evidence based medicine—or a reformation—the breakaway of a group of concerned followers from orthodoxy to form a separate school of thought. Meaningful, far reaching change will require …

The new medical model: a renewed challenge for biomedicine

Over the past 25 years, several new “medicines” have come screeching onto health care’s various platforms, including narrative medicine, personalized medicine, precision medicine and person-centred medicine. Philosopher Miriam Solomon calls the first three of these movements different “ways

Randomized controlled trials in the West African Ebola virus outbreak.

The Ebola virus outbreak in West Africa poses significant global health challenges. It marks the first time in history that the Ebola virus, a level four pathogen, has gained a foothold in a large population for a prolonged period of time. This Ebola virus outbreak has been particularly destructive as it emerged in the context of fractured, barely functioning health systems in societies slowly rebuilding after protracted and violent civil wars. High mortality rates, including the death of a large number of health care professionals, have led to further deterioration in the already poor health status of the affected communities. The economies of the affected nations have suffered. In sum, it is a true humanitarian disaster. In August of 2014, the World Health Organization (WHO) invoked the International Health Regulations and declared the outbreak a Public Health Emergency of International Concern. Shortly thereafter, in light of rapidly mounting case counts, a complete absence of effective therapy and evidence that clinical and public health countermeasures in place were inadequate to stem the tide of the epidemic, the WHO convened a group to answer the question of whether unregistered interventions should be fast tracked for potential use in the clinical management of Ebola virus. The committee decided unanimously to accelerate research, with the proviso that all efforts be made to evaluate these ‘‘in the best possible clinical studies that can be conducted under the circumstances of the epidemic in order to establish their safety and efficacy or to provide evidence to stop their use.’’ For many, the only path to achieving ‘‘interpretable data’’ is through the use of Randomized Controlled Trials (RCT). In the context of the Ebola virus outbreak, some commentators argue for both the moral and epistemic necessity of RCTs in the context of the evaluation of therapeutic agents. These claims are often accompanied by a familiar refrain that RCTs are the ‘‘gold standard’’ for evaluating therapeutic effectiveness. Others have argued that RCTs do not have the epistemic virtues claimed for them and that ethical considerations may make them less than ideal in this setting. In the financial marketplace, the gold standard has long been abandoned as a means to commensurate the value of currencies. In medicine, the time has come to abandon the practice of invoking the ‘‘gold standard’’ label as a defense of RCTs. The convention may serve a rhetorical purpose, but it does not serve in any way as an argument to justify the RCT as a methodology. There are good reasons to question the gold standard rhetoric, and explore the variety of ways in which sound inferences can be drawn in clinical research while addressing ethical concerns. In this article, we will not argue which single study design should be used above all others in the context of an Ebola virus outbreak; rather, we will argue for the kinds of scientific and philosophical considerations that must be brought to the fore.

Reasoning, evidence, and clinical decision-making: The great debate moves forward

When the editorial to the first philosophy thematic edition of this journal was published in 2010, critical questioning of underlying assumptions, regarding such crucial issues as clinical decision making, practical reasoning, and the nature of evidence in health care, was still derided by some prominent contributors to the literature on medical practice. Things have changed dramatically. Far from being derided or dismissed as a distraction from practical concerns, the discussion of such fundamental questions, and their implications for matters of practical import, is currently the preoccupation of some of the most influential and insightful contributors to the on-going evidence-based medicine debate. Discussions focus on practical wisdom, evidence, and value and the relationship between rationality and context. In the debate about clinical practice, we are going to have to be more explicit and rigorous in future in developing and defending our views about what is valuable in human life.

Philosophy, medicine and health care – where we have come from and where we are going

Professor of Applied Philosophy, Department of Interdisciplinary Studies, MMU Cheshire, Crewe, UK Associate Professor, Department of Philosophy and Religious Studies, Old Dominion University, Norfolk, VA, USA PhD student, Faculty of Medicine, University of Toronto, Toronto, ON, Canada Associate Professor, Department of General Practice, University of Auckland, Auckland, New Zealand Director, Department of Family and Community Medicine, University of Toronto Joint Centre for Bioethics, Toronto, ON, Canada Assistant Professor, Department of Philosophy, Dalhousie University, Halifax, NS, Canada Assistant Professor, Department of Philosophy, University of Guelph, Guelph, Ontario, Canada Senior Lecturer, Department of Philosophy, University of Southampton, Southampton, UK Socrates Professor in Philosophy and Technology, Technical University, Eindhoven, The Netherlands

What are chronic diseases

What kind of a thing are chronic diseases? Are they objects, bundles of signs and symptoms, properties, processes, or fictions? Rather than using concept analysis—the standard approach to disease in the philosophy of medicine—to answer this metaphysical question, I use a bottom-up, inductive approach. I argue that chronic diseases are bodily states or properties—often dispositional, but sometimes categorical. I also investigate the nature of related pathological entities: pathogenesis, etiology, and signs and symptoms. Finally, I defend my view against alternate accounts of the nature of disease.

Theory, experience and practice

Despite its potential hazards, the activity of questioning theoretical frameworks and proposing solutions is necessary if progress is even to be possible. Intellectual history has by no means ended, so we cannot expect to have all the answers, and from time to time the activity of critical questioning will be frustrating. But intellectual progress requires us to continue the process of asking fundamental questions. The alternative to thinking in this way is indeed unthinkable.