What is Evidence-Based Medicine?

Evidence-based medicine, also known as evidence-based practice, is an approach to medicine rooted in the use of controlled clinical studies to determine the best approach to medical practice. These studies are used to assess patient outcomes with a variety of treatments and interventions to determine which is the most effective for the population as a whole. While recognizing that patient outcomes can vary in response to individual factors that cannot be controlled in a study, this approach is intended to ensure access to the most effective and appropriate treatment.

Nationalized health systems rely heavily on evidence-based medicine for making decisions about practice and the treatments the government will agree to cover. For example, a government may solicit a number of studies on smoking cessation to determine the most effective approach on the basis of the evidence. This approach is the one health care providers will offer and the government will cover, although people who want to pursue other options can still do so.

Insurance companies use a similar process, evaluating studies on different treatments to determine what they will cover when patients apply for reimbursement. Evidence-based medicine is used to set a baseline standard of care so all patients receive access to the same level of treatment. As individual issues arise, doctors can use their own best judgment, combining evidence-based medicine with clinical experience. In the case of an elderly cancer patient, for example, the standard of care may dictate aggressive chemotherapy for that type of cancer, but doctor and patient could decide, upon consultation, that palliative care only should be provided.

In evidence-based medicine, the studies used for setting standards of care are often provided with ratings intended to convey information about their reliability and applicability. Ratings tend to be higher for studies with a large sample size, careful controls, and rigorous doubleblind methodology, as these are deemed less susceptible to bias and other issues known to arise in the course of medical studies, such as failing to obtain an adequate sample and missing risks as a result.

It is important to be aware that medical decisions made with the use of evidence-based medicine are sometimes characterized as “care rationing.” The goal of the evidence-based approach is not to deny people medical care, but to provide people with the care most appropriate to their needs, and not to offer care deemed unreliable, unsafe, or inefficient. In cases where the standard of care is clearly not appropriate to the needs of a patient, other options can be made available.