Evidence Based Medicine
Being a doctor entails making decisions constantly regarding patients’ care. Doctors always face dilemmas on what is the best direction to take, what is the most appropriate test, treatment or whether at all intervention is necessary. All decisions made are dependent on knowledge, skills and resources available as well as patients’ concerns and values. Knowledge and experience however, does not inform you of the latest evidence on what is the best available management. Additionally, the level of experience required can take time to establish.
The volume of information accessible is vast and a level of uncertainty can present particularly when the variety of evidence available is contradictory. Let’s consider this example: an eighty-four-year-old patient presents with unexplained loss of consciousness. CT scan requested shows leaking abdominal aortic aneurysm. It is not strange to see such a patient rushed to theatre to repair the aneurysm but, what are the odds that this patient will survive such a major operation? Is the intervention curative or simply a means to allow clinicians time to assess the best next appropriate step? This example exposes the potential gap between clinical practice and research.
Similarly, during the 1980s, patients that presented with myocardial infarction were treated with flecainide to reduce the rate of death due to arrhythmia. However, in later research it was established that flecainide increased the rate of mortality. Even though the biochemical role of flecainide in treating arrhythmia was well established, this did not translate to clinical benefit.
In essence, a clinician needs to be able to identify good evidence, but that is not always easy to do. The total number of published randomised controlled trials have increased exponentially since the 1940s. In fact, there are more than 20,000 articles published every year at the rate of 50 a day! So much evidence and so little time…
Why is it important to search for evidence?
Many medical students and doctors rely on texts books to enhance their clinical knowledge and understanding. However, most of these books contain information that has not been updated for almost a decade. Additionally, decisions surrounding patient care are a matter of sound judgement alongside personal expertise and external evidence can only serve to enhance that judgement. The fact that presentation of illnesses can vary in the clinical setting makes it more important to seek information to improve the decision-making process. For instance, a patient presents with persistent cough; differentials might include asthma, post-nasal drip, chronic bronchitis, whooping cough, etc. However, it may not be apparent that gastro-oesophageal reflux is one of the causes of dry cough. This is an example where research findings can contribute greatly to clinical experience. In contrast, lack of EBM will lead to an outdated clinical practice that is potentially detrimental to patients.
How to identify evidence that are applicable to clinical practice?
Clinical experience and external evidence are of equal importance. Developing a good clinical acumen will guide clinicians in ascertaining what is applicable, appropriate and likely to be beneficial when searching for novel treatments. Equally, doctors should develop the ability of carrying out critical appraisal and identifying valid research. The literature contains a plethora of information with varying degrees of reliability. Hence, a good grasp of the topic as well as critical analysis of presented evidence can help elucidate reproducible research.
In this monthly series of Evidence Based Medicine, we hope to shed light on the challenges that doctors face when searching for up to date evidence. Firstly, the history of scientific research will be discussed in the next post.