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Outcomes-based practice, Part 2

Feb. 1, 2001
They call far more evidence-based dentistry is an embarassing conclusion we have come to based on some old assumptions, explains Dr. David Chambers.

by David W. Chambers, EdM, MBA, PhD

In a previous article, I explained why my bet for improving the quality of oral health care rests on the individual practitioner who reflects on the outcomes of his or her unique practice. I call this approach to continuous improvement Outcomes-Based Dentistry (OBP).

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There are certainly other approaches to building better practices, almost all of them are of the "one-size-fits-all" variety. Most of them are developed someplace outside a dental office and then pushed into practices. We certainly hear a lot these days about parameters, enforcing standards of care, and evidence-based dentistry.

When dentistry became a profession roughly 80 years ago with the help of William Gies, it did so by embracing the scientific foundations for practice. Today, dentists know enough biochemistry to critically evaluate the claims of dental materials. They understand enough physiology to determine the likely action of the drugs they prescribe. Business principles and office finance are understood well enough to function effectively and to recognize when specialized help is needed. All living dentists have been trained in the scientific method, loaded with fundamentals in their dental educations, and, for the most part, they are pretty vigilant about staying current.

Conversations with colleges, reading the literature, continuing-education courses, and even formal advanced education are all means dentists use to build and maintain their knowledge base. Should it be done more often, more critically, and more selectively? Not a bad suggestion. But none of this is dentistry; it is the foundation upon which individual dental practices are built.

Dentistry will be increasingly dependent on technology for materials, equipment, systems, and even decision support. Voice-activated patient records will not stop at data capture. Logic will be included in the programs, permitting such features as alerting dentists that a tooth marked as filled on an examination several years ago cannot be charted as sound today. Another feature of decision-supported dentistry will be aids in diagnoses and treatment-planning. The automated record soon will be generating alternatives for dentists. Potential diagnoses of conditions, indicated and contraindicated medications, and even alternative dental therapies are already coming online. The computer will support dental decisions, but not make them. This is something analogous to the way your financial planner uses spreadsheets to run alternative investment strategies for your comparison.

A third alternative to OBP is the standard of care. Every dentist understands that he or she should practice above this standard. It has the advantage of differing from one jurisdiction to another, thus recognizing that dentistry is an evolving profession. The standard of care also has disadvantages. It is a minimum criteria associated with a defensive mindset and, therefore, ill-suited to encouraging continuous improvement. The standard of care is communicated informally and strategically (in order to make a point), if it is communicated at all. The ultimate authority on standard of care is the court system. Lawyers who specialize in this area generally are more knowledgeable than are dental professionals.

The worst alternative to outcomes-based practice is policy-based dentistry. There are organizations working to establish rules that prescribe specific behavior once certain conditions have been identified. The LEPAT (Least Expensive Professionally Acceptable Treatment) used by third-party payers is an example. All such rules are designed to reduce variation in treatment. This is a worthy goal, but not the ultimate one. The prime objective in oral health care is to maximize oral health. The number and complexity of individual factors operating at the point of delivering dental care overwhelms policy in all but the most simple cases. Today, we are seeing policy shift from guidelines to rules, and attempts are being made to remove judgment from the profession - whether based on evidence or on consensus. The policy-based dentistry being developed by government agencies, the ADA, specialty groups in the profession, and third-party carriers are equally suspect.

Won't evidence-based dentistry (EBD) save us from all of this? Not likely! The biggest problem with EBD is that no one knows for certain what it is. Proponents advance this or that feature, and critics attack it in other places. It is dentistry's Rorschach test for the new millennium. In a certain way, EBD is a combination of scientifically grounded practice, decision support, and policy-based dentistry. Its genealogy can be traced to problem-based medical education and a desire to ensure that physicians trained in this pedagogical approach would be respected by their colleagues when they practice as though every patient presenting is a research project. It might be fair to say that many of the EBD advocates in dentistry are the traditional researchers who have advised practicing dentists for years and now find their slim market share eroded by self-proclaimed experts on the continuing-education and .com circuits.

My concerns about EBD stick to any definition that promotes the determination of how dentistry should be practiced based on evidence acquired outside of dentist practice, or the notion that dental practice needs to be learned from or approved by someone besides practitioners. Table 1 lists contrasts between EBD and OBP.

Evidence is of value in situations where there is uncertainty. Most dentists treat situations they have encountered many times before and where the results can be predicted with great confidence. Researchers, by definition, study uncertain conditions and artificially create them to maximize uncertainty as part of the experimental model. It is bedrock in the research community that evidence must be gathered in controlled situations. In fact, the statistical formula for significance can be manipulated almost arbitrarily to ensure that research results are publishable if the environment is sufficiently standardized.

Exactly the opposite situation exists in practice, where it is impossible to standardize patients. The best dentistry is unique dentistry, customized to individual patients. The other factor that can be manipulated in science to make a fixed treatment effect more statistically significant is the sample size. Experiments can be repeated if they do not work out as well as hoped, and averages across successes and failures can be reported in the literature. Try that logic on a patient in practice!

In science, researchers seek to isolate causal factors and take particular precautions to protect the study from their personal influence. In dentistry, the causal agent is the practitioner. Dentists expect that they are the ones making the difference - not the materials, the equipment, or the scientific theory. In research, the gold standard - the randomized control trial - is based on the logic of finding some conditions where a chosen method can be proven different from another method, usually one of no practical interest. In dentistry, the result is fixed (better oral health and improved practice) and the method is varied.

There is something of a political sense to EBD. A classic paper in the EBD literature reports that only 17 percent of the procedures performed in medicine have been experimentally validated. This statistic has been quoted frequently, and the implication is that it is very important.

I do not know what this statistic means, however. Is the lesson that physicians should stop doing 83 percent of the procedures they now perform? Does it mean that the number of medical researchers should be multiplied by five? Does it mean that researchers should be forbidden from studying anything new and must focus instead only on testing the efficacy of existing medical practices? Does it mean that the appropriateness of practice should be determined by people other than the practitioners themselves? In every case, I rather think the answer is no.

The call for more translational research or evidence-based dentistry is an embarrassing conclusion we have come to based on some old assumptions about the relationship between science and practice. Good science and its understanding by the practitioner are essential, but only as the foundation for practice - not as the determiner of how practice should be done.

Next month, we will look at how practitioners learn.