The ever‐shifting source of authority on what works in clinical medicine

Given the immense complexity of illness and medicine, clinicians must rely on training, clinical experience, and research to provide information on how to best manage clinical problems that arise in a patient encounter. Practitioners of evidence-based medicine (EBM) encourage the use of up-to-date research of high methodological rigour to guide clinical decisions. However, as clinicians are rarely in a position to adequately find and assess the literature and often have limited experience with some problems that arise in day-to day practice, they often turn to trusted sources to inform them about what works what does not *. In recent decades, Cochrane systematic reviews have become the authoritative source for estimates of the therapeutic effectiveness of several interventions. With the recent “crisis” at Cochrane, some clinicians may have concerns as to the authority of such reviews. This issue of the Journal of Evaluation in Clinical Practice presents papers that examine the so-called “crisis” at Cochrane.3-6 That examination raises important questions about the role of authority in contemporary clinical medicine (including Cochrane's authoritative status). The practice of clinical medicine has always been grounded in some authority regarding how to diagnose and manage illness, whether it be a person, text, or institution †. In the classical era of Greece, clinical practice was grounded in the ideas of an individual who served as the authoritative source for small group of followers. With the development of humoral theory, Hippocrates, and later, the writings of Galen became the authoritative source for medical practice in the West. During the Middle Ages, Byzantine scholars, and in particular, Islamic scholars, recorded and standardized the knowledge of the major medical traditions (ie, Galen) into authoritative texts that also integrated the advances of Islamic medicine. Authority would shift again with the rise in the practice of autopsy. Derived from the Greek “autopsia,” which means “to see for oneself,” autopsy placed authority in the hands of the observer. Those observations were meticulously recorded by anatomists—Andreas Vesalius being the most noteworthy of Renaissance anatomists. Anatomical investigations alerted medical scholars to errors in the Galenic world view. That awareness led to new theories of health and disease, including physiological explanations rather than humoral balances. The shift to learning from observation rather than reasoning from humoral theory was part of a greater societal change shaped by what would later be known as the Enlightenment and the Scientific Revolution. As was the case in other fields, authority would not reside in the works of ancient Greek philosophers, such as Aristotle, but in the knowledge that could be generated from careful and controlled observation. So-called “scientific medicine” would leverage scientific ways of knowing and the ability of scientific knowledge to explain many phenomena in the natural world. Formal training in medicine, which became popular with the rise of the University, included learning from both authoritative texts and anatomy demonstrations (and in rarer circumstances, hands on dissections). Physicians could lean on the authoritative status of the University as a centre of knowledge and on what was learned there to give them a privileged societal position as diagnosticians and healers of ill health. The content of that learning changed over time. In the 17th and 18th centuries, it was becoming apparent that much could be learned at the bedside. Thus, a good medical education would also include clinical rotations. Clinical experience would complement knowledge of anatomy and the canon. In the 19th century, Claude Bernard (as well as other physician scientists, notably those in France) argued that reasoning from the principles of physiology—learned through scientific study—should serve as the basis for clinical practice ‡. A believer that human function was bound by the laws of nature, Bernard warned against settling for probabilistic relationships as a foundation for clinical decisions.8 Thus, clinical practice could find its authority in scientific laws. Likely because such knowledge was incomplete, clinical expertise (developed through academic learning and experience) continued to be the backbone of clinical practice through the 20th century. Authority would sit with the experienced clinician to which junior staff and learners would defer §. The value of clinical expertise was challenged in the late 20th century when researchers demonstrated unexplained variations in the use of many healthcare services and therapies among seemingly similar patients.9 In addition, researchers were starting to become suspicious (and in some cases showed) that many (if not most) therapeutic interventions in use were of little or no value in improving patient health—something Cochrane himself noted in his famous book, Effectiveness and Efficiency.10 Attempts were made to reign in both concerns through the use of practice guidelines, first developed from panels of experts, and more recently through formal “evidence-based” methods (eg, the GRADE framework11). The EBM movement shifted authority to clinical scientists and high-quality trial evidence, ¶ and did so explicitly. The EBM movement introduced an evidence hierarchy as a means to adjudicate the authority of evidence.12 At the top of the EBM evidence hierarchy is synthesized evidence, for example, systematic reviews of randomized controlled trials (RCT). These reviews go through a further synthesis when taken up by guideline panels, who integrate such information with other considerations when making recommendations for practice. While systematic reviews can be performed by many clinical researchers, prominent among such reviews are those developed through the Cochrane Collaboration (now simply known as “Cochrane”). Established in 1993, the impetus for the collaboration was Archie Cochrane's idea of a resource for clinicians that can inform them of trial results. Since then, the Cochrane systematic review has become widely recognized as the “gold” standard of evidence for estimating the effect of clinical interventions and, thus, a highly authoritative source regarding what works (and what does not) in clinical medicine. Recently, some have argued that Cochrane's golden shine has worn off. The dismissal of a highly published and influential scientist and the subsequent resignation of four members of its board of governors has made some worried about the continued authoritative status of Cochrane reviews. It has been alleged that the actions of the Cochrane leadership have favoured industry interests # and that it has allowed conflicts of interest into the systematic review process13 that have potentially corrupted the objectivity of the authors producing Cochrane reviews. The concern is that such actions may result in interpretations of evidence in Cochrane reviews that are sympathetic to the pharmaceutical and biotechnology industries. Whether those allegations have merit is at best debatable, as we have no impartial evidence for or against them **. Let us suppose (hypothetically) for a moment that those allegations are true. What impact might they have on the community? Systematic reviews are often used as the basis for evidence of therapeutic effect when developing recommendations for practice and clinical practice guidelines (eg, GRADE), which in turn are used (or are encouraged to be used by advocates of EBM) to guide resources allocation, service provision, and benchmark quality of care. Thus, reviews of evidence that have a pro-industry bias (at the expense of the patient and public) can lead health care managers and service providers to inadvertently purchase and deliver care consistent with an industry (and not necessarily patient) agenda. Sifting through and interpreting the literature to help guide clinical decisions is often not feasible in day-to-day clinical practice, nor are clinicians always experienced enough to perform such tasks adequately. For those clinicians who rely on synthesized evidence to stay up to date, a trusted source (such as Cochrane) is paramount. If the community has reason to be sceptical of Cochrane reviews (or any authoritative source), it is not clear where clinicians will turn when seeking information on what works in clinical practice. The “crisis” at Cochrane presents the health care community with a dilemma. One solution might be to abandon Cochrane produced systematic reviews as the “gold” standard. However, in doing so, the community would be tasked with finding a new authoritative source for evidence on what works in clinical practice that can and will be trusted by stakeholders in care. Gaining the trust of stakeholders is not a trivial task, especially in a high stakes environment where there exists significant financial interests that are not always aligned with what is best for the patient. On the other hand, the community could continue to leverage Cochrane's reputation for providing high-quality evidence synthesis. However, that would require assurances that allegations against Cochrane are either false or that steps have been taken to fix whatever problems exist within the organization were those allegations to be true. As Ioannidis14 suggests, that may require a significant effort and gestures of good faith by the Cochrane leadership. Authoritative sources have come and gone over the last two plus millennia of clinical medicine. Whether Cochrane will simply become a footnote in that long history is yet to be decided.

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