Evidence-Based Medicine: A Cautionary Tale

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By Thomas C. Schuler, MD, National Spine Health Foundation President

Evidence-based medicine is a term that has become ubiquitous in healthcare. The concept is that through analysis of clinical outcomes, one can identify the best way to treat a given medical condition. While the concept is exciting, findings are not generalizable to everyone and should not be used to make policy. Research allows us to critically analyze what has been done to determine what works, but the reality is that research is far from absolute. It gives us information on what may work for a given situation but is not a definitive answer.

In reality, the art of practicing medicine is complex and:

  • Evolves over time
  • Is based upon critical thinking
  • Involves intellectual and technological innovation
  • Involves the analysis of treatment outcomes to improve future treatments
  • Requires physicians to evolve treatments as new knowledge and new technology become available 
Medical insurance companies often use research findings as criteria to deny access to treatment for patients.

Inappropriate Interpretation Denies Access to Care

One significant but negative sequelae of evidence-based medicine is that medical insurance companies often use research findings as criteria to deny access to treatment for patients. While research is necessary to demonstrate and understand both positive and negative outcomes in medicine, the results are not meant to become a reason for insurance companies to deny access to care; but this is being done because insurance is a money-making business. This is most problematic for patients whose individual biology or response to treatment falls outside the generalized data that may become standardized as evidence-based medicine. Human beings and their physiology are not absolutes. We know that from DNA analysis, different people respond differently to medications and treatments. One person may metabolize medicine differently than another based upon their DNA; so regardless of what evidence-based data may show for the general public, it may not relate to each person and his or her response. This is especially true in surgical interventions and nonoperative treatments for spinal healthcare. 

Another potential downside is the comparison of different treatments to develop evidence-based medicine. As inquisitive clinicians, we must ask ourselves, “has a correct comparison point been selected and how is that relevant for a given patient?” For example, when studying the incidence of spine surgery complications, it has been shown through research that patients over the age of 70 years have a much higher complication rate than those under 70. The reality is, if age 65 or 75 had been selected as the reference point in the study, the result would have been the same. At the end of the day, a researcher picks a data point and then makes comparisons to it, but that does not make it an absolute. A healthy 70 year old should not be universally denied the treatments they need.

Another example is when studying the slippage of one vertebra on another (called spondylolisthesis) and when surgical intervention should be considered. During the study, the distance of slippage selected for comparison was 3 mm, a randomly selected number that was felt to be significant. The results of that study lead insurance companies to authorize surgery for spondylolisthesis only if the slippage is at least 3mm, but not less. This leaves many patients without access to treatment based on an arbitrary research data point. Ultimately, the patient needs surgery based on their failure to respond to non-surgical treatments and the amount of pain they are having, not on their millimeters of slippage. Maximizing profits was not the purpose of this research, yet evidence-based research is often misused by insurance companies to avoid paying for treatments. 

Many innovations that benefit patients have not been proven through evidence‑based medicine to the point that it satisfies insurance companies; therefore, these treatments are denied. Artificial disc studies have shown the technology to be extremely beneficial for patients having one- and two‑level disc replacement surgeries. However, insurance companies deny coverage for three- and four-level disc replacements, or a combination of an artificial disc at one level and a fusion at another level, because the original FDA approval studies only looked at one- and two-levels. Either of these additional surgical options may be appropriate based on the patient’s anatomy, but are completely denied by insurance companies. This is an inappropriate use of research data and incorrectly claims that since we have not proven something, it can never be done. If we take this position, medicine will never advance and patients will not have access to the best treatments that exist now or those that come in the future. 

Innovation and Customization

Evidence-based medicine is an attempt to prove what treatments work best for the general population. This is often done in hindsight, while innovation requires foresight. Innovation precedes evidence-based medicine, otherwise you could not try a new treatment if it was not proven. Anecdotal experience coupled with intellectual assessment forces a great physician to evolve for the betterment of his or her patients. If one were to only provide treatment that was proven, then innovation would not be possible. This is the Achilles heel of evidence-based medicine. 

Medical research allows us to understand responses to treatments and helps us determine which treatments are better as a whole. But we must remember that this does not determine which treatment is best for each individual since we have to take into account the anatomy, physiology, biological makeup, social and psychological situation, and personal goals of each patient. It is a truly customized and individualized approach that produces the best result for each individual patient when provided by a competent medical professional. This is critical to achieve success in spinal healthcare

We should always be striving to gain more knowledge and to be critical of the available treatments, but leaving the final treatment decision between the patient and physician to determine what is best in each situation. Evidence-based medicine can help us make informed decisions but is never an absolute answer. Patients are unique and should be treated as such.