55 On the Fundamentals and Philosophy of Evidence-Based Care, Part 1
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Dynamic Chiropractic – July 2, 2007, Vol. 25, Issue 14

On the Fundamentals and Philosophy of Evidence-Based Care, Part 1

By Robert Cooperstein, MA, DC

Review of the American Back Society Annual Meeting in Las Vegas

If the time allotted to a presenter is any indication of the importance of their presentation, the American Back Society must have thought Dr.

Genovese's presentation on evidence-based medicine (EBM) was very important, as he was given 45 minutes, rather than the usual 20 minutes. Being in favor of EBM is about as controversial as being in favor of questionable concepts like clean air and a safe water supply. But this devil is truly in the details. If the evidence were always ample and clear, there would be no problem. However, what do you do when the evidence is inadequate, conflicting or simply absent? Addressing this thorny issue was the main topic of Dr. Genovese's discussion.

In the "good old days," disease management meant clinical judgment in the practice of the art of medicine. By the 1970s, large variations in clinical practice had been noted, including the utilization of surgical procedures. By the 1980s, the RAND Corporation had become involved, formulating the opinion that many back interventions were quite unnecessary and that practice patterns were simply not based on good evidence. The 1990s witnessed the advent of clinical practice guidelines, as produced by groups of experts reaching consensus. The move toward more formal "rules of evidence" came later1 and evolved into what is now commonly known as EBM. The classic definition from Sackett is as follows: "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 clinical expertise with the best available clinical evidence from systematic research."2 Not surprisingly, the cornerstone of EBM is efficient literature searching.

It did not take long for problems with the initial formulation of EBM to surface, including unrealistic standards and dealing with situations in which there is conflicting evidence or no substantial evidence. In these situations, there continues to be a role for traditional consensus processes involving experts. In such situations, multidisciplinary panels are preferred in order to reduce bias.

The latter portion of Dr. Genovese's presentation dealt with sources of bias in biomedical research. It is still common to confound association and causation. It is never too trivial to point this out. For example, cigarette smoking leads to both increased coffee intake and heart disease, but coffee intake itself should not be concluded to be a cause of heart disease. Bias creeps into studies when either the experimental or control subjects are nonrepresentative, possibly because they have volunteered to take part in the study. In chiropractic literature, we are aware of studies in which the nontreated control groups are composed of volunteers taken from the same family as the treated subjects!

Echoing a theme commonly struck by Dr. Donelson at ABS meetings, Dr. Genovese argued against the practice of using the "category of nonspecific low back pain" in research designs, as if all mechanical low back patients were derived from a homogeneous population. Carefully defining patient subtypes greatly assists in discovering which treatments work best for particular diagnoses. Apart from experimental design issues, bias also may take the form of selective publication (deciding what and where to publish, based on the results of the study). How many negative studies are simply held back from publication? Biomedical research publishers and other constituencies have made progress in this area, now requiring researchers to register studies at their outset as a precondition to their eventual publication.3

Patient Empowerment: The Newest Component in the Decision-Making Process

Dr. Haldeman's discussion of EBM immediately followed Dr. Genovese's presentation. Whereas Dr. Genovese emphasized the process and pitfalls of implementing EBM, Dr. Haldeman focused on its implications, along with the impact on both doctors and patients. Yes, doctors are supposed to be familiar with the evidence and practice in accordance with it. But beyond that, they must be familiar with evidence on all treatment approaches, not just those within their particular specialty. The courts are saying that the patients need to know what is out there, and that the physician may not impose their opinions, including aversions to types of treatment the patient receives.

In the information age, patients have similar, if not identical, access to the information upon which physicians must rely. They commonly walk into the doctor's office armed with printouts from Medline on the advantages and disadvantages of different diagnostic and treatment procedures - not unlike a consumer showing up at an auto dealership with stacks of printouts on automobile options and add-ons, much to the chagrin of the salespeople. Modern patients may ask for references to back up the physician's recommendations. The concept of informed consent has now been expanded to include the demand that the patient be given a measure of control over the decision to accept or reject recommended diagnostic tests and treatment approaches.

Dr. Haldeman had a number of recommendations:

  • Physicians must become skilled, but in the meantime, should leave the education of patients and discussion of clinical options to other doctors with greater understanding of the evidence and treatment options.
  • Physicians must take the time to educate themselves and become experts on more than their favored treatment approaches, and avoid excessive claims and enthusiasm for their favored approach.
  • The central goal is to empower patients to understand the risk and prognostic factors, so as to have the information it takes to make informed decisions about their care.

Dr. Haldeman also noted that in California's Monterey County, prosecutors recently won a $25,000 judgment and an injunction against a Watsonville chiropractor in a case involving deceptive advertising. The chiropractor had propagated "absolutely false" information on the DRX-9000 traction device, claiming that NASA had discovered that "outer space quickly and easily solves 86 percent of back pain."4

Artificial Disc Replacement for the Cervical and Lumbar Spines

Since I have covered the advent of the artificial intervertebral disc in previous columns,5-7 I thought it best to comment on Dr. Hannibal's update on total disc replacement (TDR). Yes, we do have to update this topic every year. The landscape has changed completely, with new designs and more data coming in all the time. There is a huge patient demand and huge corporate interest in it, given the fact that TDR appliances are very profitable. This is all associated with a huge informational media blitz, some flattering and some very negative on the TDR. The truth, according to Dr. Hannibal, is in the middle.

Motion preservation is the key to understanding interest in the TDR. Although laminectomy and fusion are still the standards, the latter especially transfers the biomechanical stress to another spinal level, often leading to future spinal problems. Dr. Hannibal said that the TDR has outperformed fusion procedures in several studies. Devices now in use include Maverick, Prodisc, Charite Link III, and FlexiCore Kineflex, among others. The Charite device is currently approved for single levels, but the multi-level procedures did not work as well. It seems that too many surgical procedures were performed by inadequately trained doctors, which then led to negative press and, ultimately, fewer procedures. There are now dozens of cervical disc-replacement devices on the market. The cervical designs show more variability than the lumbar ads. In his concluding remarks, Dr. Hannibal stated that motion preservation technology is here to stay, even if it is still in its infancy.

We note Dr. Haldeman's comment in his earlier talk. There are 11 studies that show nonsurgical spine treatment and fusion surgery get equal outcomes, while the justification for TDR is that it gets outcomes comparable to fusion surgery. We must compare this against Dr. Hannibal's claim that TDR works as well, if not better than fusion, and with much faster recovery time.

Vertebroplasty and Kyphoplasty

Having discussed TDR, it is of interest to briefly note Dr. Kondrashov's discussion of another relatively new surgical technique to treat painful vertebral compression fractures. Vertebroplasty is the injection of bone cement (usually polymethyl methacrylate, commonly known as Plexiglass) into a vertebral body. Kyphoplasty is the placement of a balloon in the vertebral body to create a cavity prior to the injection of the bone cement. These procedures are performed on an outpatient basis. The cement is so strong that if the spine is loaded to pre-injury level, the implant will be viable after other structures fail. The indications may include any cause of vertebral body collapse, including malignancy and osteoporosis. Since there are significant risks associated with these procedures, the patients receiving them must be carefully selected to make sure there is a favorable risk-benefit ratio. The future of these procedures is uncertain, as there are no level 1 studies for either.

For further reading, consult the following references.8-10 Part 2 of this article will include further conference coverage.

References

  1. Guyatt GH, Kirshner B, Jaeschke R. A methodologic framework for health status measures: clarity or oversimplification? J Clin Epidemiol, 1992;45(12):1353-5.
  2. Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS. Evidence-based medicine: what it is and what it isn't. BMJ, 1996;312(7023):71-2.
  3. International Clinical Trials Registry Platform.
  4. Ibid.
  5. Cooperstein R. "ABS Annual Meeting: San Francisco, Nov. 16-19, 2005 (Part 2 of 2)." Dynamic Chiropractic, 2006;24(12). www.chiroweb.com/archives/24/12/06.html.
  6. Cooperstein R. "The 2003 Meeting of the American Back Society, Part 2." Dynamic Chiropractic, 2004;22(17). www.chiroweb.com/archives/22/17/05.html.
  7. Cooperstein R, Morschhauser E. "ABS Meets in Orlando, Part 2." Dynamic Chiropractic, 2002;20(14). www.chiroweb.com/archives/20/14/05.html.
  8. Garfin SR, Buckley RA, Ledlie J. Balloon kyphoplasty for symptomatic vertebral body compression fractures results in rapid, significant, and sustained improvements in back pain, function, and quality of life for elderly patients. Spine, 2006;31(19):2213-20.
  9. Taylor RS, Fritzell P, Taylor RJ. Balloon kyphoplasty in the management of vertebral compression fractures: an updated systematic review and meta-analysis. Eur Spine J, 2007.
  10. Taylor RS, Taylor RJ, Fritzell P. Balloon kyphoplasty and vertebroplasty for vertebral compression fractures: a comparative systematic review of efficacy and safety. Spine, 2006;31(23):2747-55.

Click here for previous articles by Robert Cooperstein, MA, DC.

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