David Sackett was widely known as the “father of the evidence-based medicine” movement recently died. He defined evidence based medicine (EBM) as the “conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.” It is a set of best practices based on rigorous experimental data and seeks to provide health practitioners with effective treatments that have been evaluated by double blinded randomized controlled trials (RCTs). The goal of EBM is to transform the “art of medicine” into the data dependent “science of medicine.” It involves the interpretation of current scientific literature and developing generalizable clinical practice guidelines for the entire population. Although EBM is a worthy pursuit, in our current medical landscape, it is at best a lofty ideal but forced and rigid adherence to these guidelines are detrimentally and even potentially dangerous for our patients.
Even though RCTs serve as an excellent framework for conducting an experiment they are poor representatives of the general population. They are often characterized by narrow inclusion criteria and recruitment and often fail to enroll a sample that is representative of the population. According to one study, non-representativeness is probably the rule rather than the exception. Are the results of a study in Europe or Asia applicable to the United States? Are the results of a study in men applicable to women? Are the results of a study in Caucasians applicable to African Americans or vice versa? Interpreting results from these studies without taking into consideration individual patient specific factors could result in dangerously discounting the differences between our individual patients and those studied in the primary trials resulting in over/undertreating.
During my medical practice, I am offered “evidence based” best practices in a variety of clinical encounters, however, these do not take into account the complex environmental milieu of my patients nor do they replicate the multifaceted patient-physician encounter. External factors such as food availability, income, education, health care accessibility, and patient preferences all factor into a clinical encounter and the health status of a patient but these critical determinants of health for the most part are ignored in EBM guidelines. By some estimates, the social determinants of health account for almost 70% of health outcomes. The sum of the environment’s contribution to health (or disease) has been conceptualized as the exposome and until this can be further elucidated, these guidelines will be lacking granularity to sufficiently treat an individual utilizing solely EBM guidelines. Nevertheless, many clinicians are being discouraged from using their clinical judgment in favor of rote guideline adherence.
In my opinion, the lack of mechanistic knowledge of the environment on health (and disease) is a significant cause of variation in treatment effects. EBM formulates best practices for general populations, however, I treat individuals in a very specific set of environmental conditions under the guidance of very specific genomes. Without good data on a patient’s “exposomic” risk, clinical trials provide incomplete (albeit the best available) guidance for treating that individual. However, average effects most often pertain to the average patient and clinicians should be wary of falling into casual compliance with practice guidelines that do not account for the possibility that treatment effects are variable. More importantly, clinicians should not be systematically discouraged from using their clinical judgment by the over-implementation of rigid clinical recommendations and practice standards.
The ideal for many of us is to transform the “art of medicine” into the “science of medicine.” However, the current lack of data on the exposome makes that a yet unachieved goal. In the interim, we should be careful imposing rigid clinical guidelines on physicians that take away from their ability to consider patient specific factors in their decision making that is unaccounted for in current iterations of practice recommendations. Even David Sackett recognized the limitations of current EBM and recognized the importance of bedside physician decision making as he stated, “the practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.”