Using Evidence-Based Medicine to Make Decisions About Treating Our RA
My wife calls me a science geek and it’s true. My current students know this geekiness firsthand because of the exuberance expressed while teaching research and statistics. In high school and college, a love of science as a way to explain the natural world developed from the influence of exemplary teachers. Since being thrown headfirst into the world of rheumatoid arthritis, it’s only natural to apply this background to all aspects of the disease in order to better understand symptoms, diagnoses, treatments, and progression.
It’s not uncommon to read a post on this site or the associated Facebook page about how some treatment, lifestyle change, or diet did or did not make a RA patient feel better. Thousands of cures and treatments for arthritis are hawked to unsuspecting patients on the Internet. A simple search reveals such claims as “The Six Week Arthritis Cure” (actually from a well known medical doctor), “14 Home Remedies for Arthritis”, “There is a Cure for Arthritis”, “New Arthritis Lotion”, “Natural Joint Relief”, and of course there’s the ubiquitous “Gluten-free Diet Arthritis Cure”. The doctor who started the gluten-free fad even recently recanted and indicated that gluten intolerance may not exist and may have more to do with poor absorption of carbohydrates (Gibson, 2013).1,2 How is a patient supposed to make decisions about all of this information? Given the overwhelming glut of information, patients need to be armed with knowledge in order to be good patients and consumers. This is where evidence-based medicine comes into play.
Evidence-based medicine is used as the foundation for the current training and practice of medical doctors, physical therapists, pharmacists, and nurses. It is the norm in the Western world. According to Sackett, et al (1996),
“Evidence-based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinicalexpertise with the best available external clinical evidence from systemic research.”3
There are multiple sources of evidence ranging from opinions of authorities to the ultimate source of evidence - the randomized control trial (RCT).4 The RCT is the “gold standard” of medical research. In a RCT, patients are randomly assigned to either receive a treatment or placebo.5 Government regulations require the extensive use of these designs for the approval of medical treatments. For drug approval, years of development and testing are required from testing on animals through three phases of clinical trials on humans.6 The vast majority of potential drugs never make it past the first or second phase of testing.
Strict experimental designs are required for drug clinical trials. Such trials usually include large numbers of patients in order to increase probabilities that the drug will impact a large number of patients. Studies include a control group which involves a group of patients who do not receive the medicine being studied – a placebo. In a RA related study, the placebo group may receive a sugar pill or a saline solution. They are also usually double blind meaning that neither the patient nor the scientists know what treatment the patients are receiving in order to minimize bias.
Let’s take an example from a popular biological treatment for RA – Enbrel. After a group of scientists proposed this biological drug as having potential to treat rheumatoid arthritis, a drug company ran multiple phases of clinical trials with thousands of RA patients and collected data on multiple symptoms. They reported,“A higher percentage of patients treated with Enbrel and Enbrel in combination with MTX achieved ACR 20, ACR 50, and ACR 70 responses and Major Clinical Responses than in the comparison groups.”7 Those patients who received Enbrel had fewer symptoms than the placebo group. Results like this along with other studies served as the basis for the approval of this drug by the U.S. Food and Drug Administration (FDA). Since its approval and use in clinical practice over many years, Enbrel has helped countless RA patients. However, a bit of caution must be used when interpreting clinical trial results. Not all patients who received Enbrel responded to the treatment. In fact, upwards of 20-40% of RA patients do not respond to anti-TNF drugs like Enbrel (Roth & Finckh, 2009).8 Those who did respond still might have symptoms of RA but to a lesser extent.
In evidence-based approaches there is a range of possible qualities of evidence. Balshem et al (2010) ranks the ranges on a scale from very low quality to high quality evidence.9 The approval of Enbrel based on the results discussed above would rated as high quality evidence. Based on this evidence, it gets prescribed for millions of RA patients. At the lowest end of the evidence quality continuum would be treatments that have little or conflicting evidence. An example of a treatment at this level would be platelet-rich plasma (PRP) where a patient’s blood is drawn, platelets are separated from other blood components, and the concentrated solution is injected into a joint that has tissue damage in an effort to jump start a healing process.10 This approach is quite popular with professional athletes but clinical trails show mixed results (Harmon & Rao, 2013).11 Personally, I’ve struggled with a torn tendon in my elbow that doesn’t seem to respond to conservative treatments such as rest, immobilizing, and physical therapy. My orthopedic surgeon wants to try PRP as a last ditch effort before doing surgery. His argument is that in spite of the lack of evidence on its effectiveness, it is relatively inexpensive and not as invasive as surgery. Since there is a lack of evidence, it is not approved by the government or insurance.
In a review of the subject of evidence-based medicine, Dawes, et al (2005) concluded that health care professionals should be able to "distinguish evidence from propaganda, probability from certainty, data from assertions, rational belief from superstitions, and science from folklore."12 It stands to reason that patients would be wise to also follow these principles in conjunction with their health care providers in order to maximize treatment response.
There are, however, limitations and criticisms of evidence-based models including that treatments are broadly applied like recipes to all patients and controlled experiments are difficult and expensive to conduct.13 The alternative to evidence-based medicine is called Complementary and Alternative Medicine (CAM) that includes practices and treatments which are not part of evidence-based medical systems. CAM includes treatments such as dietary supplements, acupuncture, spinal manipulation as done by chiropractors, and homeopathy.14 These systems of treatment are typically not vetted by evidence-based research. This lack of evidence has not stopped the growth of CAM throughout the country.
Understanding the processes of research helps patients understand the benefits and limitations of treatments. This also leads to personal application. I once had a doctor tell me that he only wants to change one medication at a time in order to determine cause and effect. That’s a smart move in order to find out what each drug is doing. In some ways, each patient is a mini experiment trying to find out what treatments impact symptoms. But the limitation is that it is a sample size of one - hardly enough to make generalizations to other patients since everyone responds differently. I also read various patient experiences on website discussion boards and drug review sites. While such individual reactions may be interesting and worthwhile for gaining perspective, they must be interpreted with caution, as they may not be based on sound scientific methods and sample sizes. Patients must understand the limitations of such discussions. Just because a medication didn’t work for me or caused side effects does not mean it won’t work for someone else. Sometimes, too much negative information ends up on such sites driving patients to fear resulting in refusal to take medications. Patients must understand the processes of evidence-based medicine and be good consumers of the plethora of information that comes our way.
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