In this blog post, we’ll explore the concept, characteristics, limitations, and future direction of evidence-based medicine—an approach that evaluates medical decisions based on scientific evidence.
What Is Evidence-Based Medicine?
A patient visited the hospital, distressed by a persistent cough and sleepless nights caused by it. After asking a few questions and conducting a physical examination, the doctor checked relevant information on a computer, diagnosed the patient with adult asthma, and prescribed a low-dose inhaled steroid. So, what process did the doctor follow to reach this diagnosis? Today, one of the key foundations for medical decision-making is Evidence-Based Medicine (EBM). At first glance, EBM appears to be a highly rational and flawless approach to medical decision-making. However, we need to think a little more deeply about whether EBM is truly always the most rational and valid method. We will now examine what Evidence-Based Medicine (EBM) is, what kind of evidence it uses to make medical judgments, the issues it faces, and the direction in which it should evolve.
Evidence-Based Medicine (EBM) is an approach to making medical judgments based on the results of systematically conducted scientific research. It involves utilizing evidence accumulated through various studies—such as randomized controlled trials (RCTs), systematic reviews, and meta-analyses—and combining this with the physician’s clinical experience and the patient’s values and preferences to provide optimal care. Today, evidence-based medicine is understood not merely as following research results, but as an approach that integrates scientific evidence, clinical experience, and the patient’s individual circumstances.
Before evidence-based medicine became established, medical judgments regarding a patient’s illness often relied heavily on the individual physician’s clinical experience. Of course, a physician’s clinical experience remains a very important factor in the diagnosis and treatment of diseases even today. The common saying, “A doctor at a certain hospital is good at treating a particular condition,” implies that the doctor has accumulated extensive experience by treating that condition over a long period, reflecting the fact that such experience can contribute to improving the quality of diagnosis and treatment.
However, no matter how important a factor it may be, there are limitations to care that relies solely on a doctor’s personal clinical experience. Different doctors may arrive at different diagnoses or treatments for the same condition, and in some cases, this can lead to overprescription. A prime example of this problem is the past practice at some medical institutions of overprescribing antibiotics even for simple viral colds. Although this practice has improved significantly thanks to stricter regulations and guidelines on the appropriate use of antibiotics, it remains a significant case study illustrating the limitations of medical care that relies solely on individual experience.
Evidence-based medicine emerged to overcome these limitations. Its core premise is that medical decisions should be based on reliable scientific research findings rather than on the fragmented experiences or intuition of individual physicians.
Today, evidence-based medicine has established itself as a core principle in healthcare systems around the world. In South Korea as well, efforts to establish evidence-based medicine—led by the medical community and academia—are continuing steadily, and various clinical practice guidelines are being developed based on this approach. Evidence-based medicine is also included as an essential component of medical school curricula, and national-level initiatives to support clinical research and generate evidence are ongoing. Furthermore, these principles are being widely applied not only to the care of individual patients but also to the formulation of public health policies and the development of healthcare systems.
What criteria does evidence-based medicine use to make medical judgments?
In evidence-based medical practice, clinical practice guidelines are generally consulted to assess a patient’s condition and determine a course of treatment. The level of recommendation in these guidelines is determined by the reliability of the scientific evidence supporting the issue at hand, and this assessment is based on a hierarchical classification of evidence levels.
Generally, the opinions of individual experts or isolated case reports are evaluated as relatively low levels of evidence. Higher levels include case-control studies and cohort studies, while randomized controlled trials (RCTs) are recognized as providing even stronger evidence. Furthermore, systematic reviews and meta-analyses—which comprehensively analyze multiple randomized controlled trials—are often evaluated as representing the highest level of scientific evidence.
In this way, evidence-based medicine helps physicians make judgments about the various issues they encounter in clinical practice based on objective scientific evidence. This approach is characterized by “objectivity” and “generalizability.” However, it is precisely these two characteristics that have led to various criticisms.
What are the limitations of evidence-based medicine?
Evidence-based medicine enables physicians to address the individual and specific problems they encounter in clinical practice in a more generalized manner, based on objective scientific evidence. While this approach has played a major role in enhancing the consistency and reliability of medical care, there are still issues regarding its core principles of objectivity and generalizability that require further examination.
First, let’s examine the issue of objectivity. In modern science, for specific research findings to be recognized as objective scientific evidence, they must undergo various verification processes, including peer review. This means that the objectivity of a specific research finding does not imply absolute truth, but rather that it is a study trusted by many researchers and capable of being replicated. The historian of science Steven Shapin has also explained that scientific objectivity is influenced by trust and social consensus formed within the scientific community. In other words, the objectivity of scientific evidence is not entirely independent or absolute; rather, it is closely linked to social processes.
Next is the issue of generalization. Randomized controlled trials, which play a crucial role in evidence-based medicine, provide a high level of evidence through rigorous research design; however, they cannot perfectly reflect the unique circumstances of every patient encountered in actual clinical practice. Actual patients possess a wide variety of characteristics—such as age, underlying medical conditions, living environments, socioeconomic conditions, and medications currently being taken—and these factors may differ significantly from those of the study participants. Therefore, there are certain limitations to applying research results directly to all patients.
This issue of generalization is a concern not only in the medical field but also in other social domains where scientific evidence is utilized. For example, in a courtroom, the specific nature of individual cases and concrete evidence are treated with great importance. If one places excessive emphasis on generalized scientific evidence without sufficiently considering the unique characteristics of individual cases, the result may fail to properly reflect the context of the actual case. Therefore, the use of scientific evidence must always be accompanied by a thorough review of individual cases.
In what direction should evidence-based medicine develop in the future?
Does this mean that evidence-based medicine, with these limitations, is a flawed theory that should be discarded? It is difficult to say that this is necessarily the case. Evidence-based medicine has established itself as a core principle of modern medicine over the past several decades and is widely utilized in medical settings around the world, including South Korea. Indeed, it has significantly contributed to improving the quality of care, reducing unnecessary treatments, and providing safer medical services to patients.
Therefore, what is needed is not to reject evidence-based medicine itself, but to continuously examine how it functions in reality and address its limitations. In particular, it needs to evolve toward a model that considers patients’ values, preferences, psychological state, and social environment, rather than relying solely on scientific evidence as an absolute standard.
Today, evidence-based medicine is also evolving in this direction. Modern evidence-based medicine adopts as its core principle a decision-making process that considers the most reliable scientific evidence, the physician’s clinical experience, and the patient’s values and preferences together. In other words, patients are not merely passive recipients of a physician’s judgment but active participants in the treatment process, while physicians serve as experts who base their decisions on scientific evidence while comprehensively considering each patient’s individual circumstances.
From this perspective, objectivity can also be understood not merely as scientific fact but as a concept that broadly takes into account the diverse environments and contexts in which patients find themselves. Evidence-based medicine can only become a more comprehensive approach to healthcare when it respects the results of scientific research while also reflecting the unique characteristics of individual patients.
While traditional evidence-based medicine has the advantage of ensuring that a physician’s care is based on high-quality scientific evidence, it also carries the risk that, in some cases, the physician’s clinical experience and the patient’s individual circumstances may not be sufficiently reflected. In this respect, evidence-based medicine can be described as a double-edged sword. However, if we develop an broader understanding of objectivity and move toward a balanced integration of scientific evidence, clinical experience, and patients’ values and preferences, these limitations can be significantly mitigated. Ultimately, such progress is expected to enable more rational medical decision-making and contribute to creating a healthcare environment where patients can place greater trust in their doctors’ judgments.
