The promises and pitfalls of evidence-based medicine

Evidence-based medicine (EBM) aims to address the persistent problem of clinical practice variation with the help of various tools, including standardized practice guidelines. While advocates welcome the stronger scientific foundation of such guidelines, critics fear that they will lead to "cookbook medicine." Studies show, however, that few guidelines lead to consistent changes in provider behavior. The hopes, fears, and mixed record of EBM are rooted in the traditional professional perspective of the clinician as sole decisionmaker. Multifaceted implementation strategies that take the collaborative nature of medical work into consideration promise more effective changes in clinical practice.     

The personalised medicine. A paradigm of evidence-based medicine

The practice of "evidence-based medicine" aims at the conscientious, explicit and judicious use of the current best evidence in making decisions about the individualised patient care. The clinical genetics evolved from translational genetics research and contributes to the clinical care of patients and families through evidence-based health care in managing inherited disorders through accurate diagnosis, molecular pathology and assessing phenotypic correlations. Translational genetics and genomics research has led to the development of powerful tools for clinical diagnosis, assessing individual's genomic profile for disease prediction/prevention, high-throughput genome-wide screening for predisposition and/or protection to complex medical conditions, and discovery and development of new drugs and vaccines. Gene mapping and deciphering pathogenic mutations have helped in unravelling the basic biological mechanisms leading to new drug discovery and development. Targeted pharmacotherapy is now possible for managing the highly penetrant multi-system dominantly inherited conditions. Notable examples include rapamycin (sirolimus) in suppressing the mTOR pathway associated hamartomas in dominantly inherited cancer family syndromes and angiotensin converting enzyme receptor blockers (ACE-RB) in preventing aortic dilatation in Marfan syndrome and related familial arteriopathies. The translational genomic research is the essential prerequisite for developing sound evidence-based diagnostic, therapeutic and prognostic clinical protocols for the practice of personalised clinical medicine.     

The need for evidence-based medicine.

As physicians, whether serving individual patients or populations, we always have sought to base our decisions and actions on the best possible evidence. The ascendancy of the randomized trial heralded a fundamental shift in the way that we establish the clinical bases for diagnosis, prognosis, and therapeutics. The ability to track down, critically appraise (for its validity and usefulness), and incorporate this rapidly growing body of evidence into one's clinical practice has been named 'evidence-based medicine' (EBM).     

The evidence that evidence-based medicine omits

According to current hierarchies of evidence for EBM, evidence of correlation (e.g., from RCTs) is always more important than evidence of mechanisms when evaluating and establishing causal claims. We argue that evidence of mechanisms needs to be treated alongside evidence of correlation. This is for three reasons. First, correlation is always a fallible indicator of causation, subject in particular to the problem of confounding; evidence of mechanisms can in some cases be more important than evidence of correlation when assessing a causal claim. Second, evidence of mechanisms is often required in order to obtain evidence of correlation (for example, in order to set up and evaluate RCTs). Third, evidence of mechanisms is often required in order to generalise and apply causal claims.     

循证检验医学与检验医学的发展

循证医学是以证据为基础的医学，循证医学在检验医学的应用即为循证检验医学。其主要实施策略是发现和提出问题；寻求实验室或者文献中的有价值证据；进行实验或方法学的评价；应用于临床检验的实践中；评价实践结果。循证医学和循证检验医学对检验医学的学科发展和临床工作的开展具有重要的意义。     

The need for evidence-based, non-drug medicine

Evidence-based medicine (EBM) is defined as "the integration of best research evidence with clinical expertise and patient values." EBM is based on three equally important key factors: i) the best available scientific evidence; ii) the physician's experience and intuition; and, iii) the preferences and values of the patient. EBM uses a hierarchy of evidence and critical appraisal of the sources, which makes it possible to balance high quality evidence with documented effectiveness. A treatment that is more safe and effective, but less well documented may very well be the treatment of choice. Ethics (not putting the patient at risk of harm with a treatment if this can be avoided at all) is an important part of EBM. Many pharmaceutical drugs have a number needed to treat (NNT) of approximately 20 [NNT=20, confidence interval CI (5-50)] and the number needed to harm is less well understood and documented. The adverse effect profile of pharmacological agents can be more harmful than non-drug medicine. Most EBM-treatments are likely to be non-drug treatments in the future. There are six steps to the practice of EBM: i) the patients and the physician must work together to define the problem; ii) the patients and the physician must explore the patient's values and preferences; iii) the information about the possible alternative medical interventions must be discussed and critically appraised; iv) the best, relevant evidence must be applied to the patient as a treatment or cure; v) together, the patient and the physician must evaluate how useful the intervention was; and vi) if the intervention did not help sufficiently, the process must begin again. In this review, we explain, in our opinion, how non-drug EBM should be practiced.     

Fundamental shortcomings of evidence-based medicine

The development of any scientific theory has a certain logic. Bruno Latour formulated a theory, describing the development of science and technology. Outcomes of science are not guided by nature or "the truth", but by a complex negotiation. It starts with ideas, which follow paths of publications and assessment. Then they are either rejected or accepted. Analysing the development of evidence-based medicine with Latour's theory, we find two fundamental problems. First, EBM tends to standardise moral considerations. Second, EBM standardises the patient, since test populations are usually composed homogeneously. Presumptions concerning methods and morals are slid into the EBM-methodology during its development. With Latour we should say, that the conceptions of the standard patient and standard morals have been delegated to this methodology. They are carried out strictly, and this causes the discomfort with practitioners and scientists within EBM. A solution should be sought for in redesigning trials, in a less morally charged fashion, and concerning less standardised patients.     

Limited possibilities for the evidence-based treatment and prevention of postherpetic neuralgia

Postherpetic neuralgia is a disorder that occurs frequently in the elderly. As the effect of the treatment of postherpetic neuralgia is often disappointing, studies have focussed on the prevention of this complaint. A commonly used preventive intervention is the administration ofa single epidural injection of a local anaesthetic and a corticosteroid, combined with oral antiviral agents and analgesics. In a large, multicentre, randomised controlled trial, the investigators found that the single injection of a corticosteroid and a local anaesthetic had no added value in the prevention of long-term postherpetic neuralgia.     

Successful teaching in evidence-based medicine

OBJECTIVES: Several published articles have described the importance of exposing medical trainees to the 'new paradigm' of evidence-based medicine (EBM). Recognizing this, we sought to develop and objectively evaluate a mini-course in EBM for third-year medical students. DESIGN: We developed a mini-course consisting of four sessions in which students learn to derive sequentially focused questions, search MEDLINE, review articles critically and apply information from the literature to specific clinical questions. To evaluate the teaching intervention, we performed a controlled educational study. Students at the intervention site (n=34) attended the EBM mini-course, while students at the control site (n=26) received more 'traditional' didactic teaching on various clinical topics. Intervention and control students were surveyed immediately before and after the mini-course to assess changes in reading and literature searching skills, as well as a tendency to use the literature to answer clinical questions. SETTING: Boston University School of Medicine. SUBJECTS: Third-year medical students. RESULTS: The intervention was associated with significant changes in students' self-assessed skills and attitudes. MEDLINE and critical appraisal skills increased significantly in the intervention group relative to the control group (significance of between group differences: P=0.002 for MEDLINE and P=0.0002 for critical appraisal), as did students' tendency to use MEDLINE and original research articles to solve clinical problems (significance of between group differences: P=0.002 and P=0.0008, respectively). CONCLUSIONS: We conclude that this brief teaching intervention in EBM has had a positive impact on student skills and attitudes at our medical school. We believe that the key elements of this intervention are (1) active student involvement, (2), clinical relevance of exercises and (3) integrated teaching targeting each of the component skills of EBM.     

Teaching evidence-based medicine more effectively

Evidence-based Medicine (EBM) is becoming an integral component of graduate medical education competency and a requirement for grad medical education practice-based learning core competency. This study tries to compare the efficacy of conferences utilizing small-group discussions with the traditional conference method in enhancing EBM competency. The participants in this randomized controlled trial (RCT) were 170 members of the medical faculty who were divided into two groups of 86 (intervention) and 84 (control). Following the intervention, EBM competency was assessed by a written examination. statistical analysis made use of chi-square test, independent sample t-test and relative risks for univariate analysis. Mantel-Hanszel was used for bivariate analysis. Cox proportional hazard models were used to evaluate multivariate-adjusted associations between EBM educational intervention and EBM knowledge, attitude and skills. A new indicator of number needed to intervention (NNI) was defined and computed. Results: The results proved conference along with small-group discussion to be a more effective teaching method with P=0.001 on knowledge, P<0.001 for attitude and skills P<0.001 in an EBM exam when compared with medical faculty members who did not participate in EBM educational intervention (n=84). Moreover, they had also increased confidence with critical appraisal skills, and searching EBM resources. Conclusions: Conferences followed by small-group discussions significantly enhance EBM knowledge, attitude, critical appraisal skills and literature review skills.