Beyond Belief: How Evidence Shows What Really Works

Something curious happens when one learns about evidence-based medicine (EBM): many things in other areas of life that once seemed self-evident begin to invite skepticism.Is the new school program effective?Has anyone properly evaluated it?What about this conservation initiative, public policy, or management strategy?In Beyond Belief, science journalist Helen Pearson explores how the principles that allegedly transformed medicine -particularly the use of randomized trials and systematic reviews -have spread into fields as diverse as social science, policing, conservation, business, education, and parenting.A central question drives the book: how can something "logical and intuitive," like looking for the best available evidence before making important decisions, be "extraordinarily hard to achieve" (p.11)?Pearson begins with the origins of EBM and its most influential figures, including Archie Cochrane, David Sackett, Iain Chalmers, and Gordon Guyatt.Although this history will be familiar to many readers with an interest in EBM, the authors' extensive interviews with Chalmers, Guyatt, and numerous pioneers from other disciplines give the narrative a fresh and engaging perspective.One of the book's strengths is its recognition that EBM is more than a hierarchy of study designs.Pearson gives considerable attention to the more nuanced and contemporary interpretations of EBM associated with family physician Trisha Greenhalgh, emphasizing the integration of evidence with professional judgment, patient values, and context.The book also highlights important contributors who are often overlooked.Among them are Frances Oldham Kelsey, who denied Food and Drug Administration approval of thalidomide in the United States, and Patricia Crowley, who performed the systematic review of antenatal corticosteroids and whose forest plot features in the Cochrane Collaboration's logo.The parallels between medicine and other disciplines are among the most interesting aspects of the book.Similar challenges emerge repeatedly across fields, suggesting that many barriers to evidence-informed decision-making may not be disciplinary but human.One example is the "positive study effect."A randomized experiment suggesting that arresting domestic violence offenders reduced repeat violence received widespread attention and rapidly influenced policy.Subsequent replications and careful reanalysis, which produced less convincing results, attracted far less notice.The same pattern is familiar to clinicians: positive findings are often amplified, whereas contradictory evidence struggles to achieve comparable visibility.Pearson also shows that generating evidence is only part of the challenge.Conservationists, educators, policymakers, and clinicians all face a common problem: once evidence summaries are available, how can they be incorporated into everyday practice?A similar problem in medicine would be antibiotic prescribing practices, which are not conditioned only by prescribers' knowledge. 1 An argument used against experiments is that they are unnecessary when the rationale and pretest probability are robust.Sometimes, that may be the case.One study, for example, found that drivers stopped at random breath-testing checkpoints viewed the police more positively when officers followed a brief script emphasizing courtesy and respect.