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MyView: You have to shake your head

October 20, 2014

By Kerry K. Carney, D.D.S.

Photo of Dr. Carney
Kerry K. Carney, D.D.S.
A new "risk-based" dental insurance plan was introduced last January by a well-known dental benefit corporation serving Michigan, Indiana and Ohio. In this new plan, the number of annual cleanings is underwritten according to patient need. The number of annual cleanings can be reduced to one unless a patient can document specific risk factors.
The risk factors specified in its online questionnaire included, for example, periodontal disease, pregnancy, diabetes, radiation therapy, suppressed immune system, renal failure, stroke or heart attack. Based on the increased risk attributable to these factors, the patient could receive up to three additional cleanings per year.

Establishing risk factors can be tricky. One has to consider the best evidence available. The risk factors themselves may not be casually related to the presence or absence of a disease or condition. Though not the cause, a risk factor may be a proxy for a casual factor or a set of conditions that enhance the disease process.
A risk factor may appear to have a high associative or predictive correlation with the disease or condition, but that powerful association may be disproven over time.

The safest course is to rely on an acknowledged authority for established risk factors. In this case, the dental benefit corporation cited risk factors delineated by the American Academy of Periodontology and a University of Michigan study. All of this sounds pretty good so far. Risk-based plans, if designed properly, can be beneficial for plan purchasers.

Now comes the screwy part. The dental benefit corporation did not include all the risk factors recognized by the AAP/Michigan study. The new plan explicitly excluded smoking as a risk factor. In a letter sent to its network of dentists, the dental benefit corporation elaborated on the thinking behind the exclusion of smoking from the list of risk factors that would warrant additional cleaning benefits.

The plan is not meant "to reward employees for 'bad behaviors' … employees who smoke will not be eligible for the additional cleaning unless they develop the disease."

If a patient came to me with a positive genetic test for the interleukin-1 gene, my first question would always be, "Why did you get this test?" Any discussion about the usefulness of this test would have to involve the questionable importance of such a test compared with the recognized risk factors associated with periodontal disease (for example, smoking).

I have argued previously for increased screenings by dentists in order to facilitate the patient's access to care through appropriate referral to a physician for diagnosis and treatment. However, this interleukin-1 test could be a toboggan on that slippery slop hurdling toward "the detection of abnormalities that are not destined to ever bother us."

The ease and popularity of cheek-swab genetic tests can give false importance and verisimilitude to a factor of little or no merit when it comes to specific risk. A genetic test may be very precise in its results but that result does not tell us about the relationship of the disease condition to the factor that is the focus of the test. That relationship must be defined through rigorous scientific testing.

Genetic tests can be very appealing to both doctor and patient. Our training in evidence-based science should make us highly skeptical of tests that purport to aid diagnosis and treatment planning. We have the ability to verify claims in the literature and we should not hesitate to voice our distrust of specious argument and spurious reasoning when it comes to our patients' care.

As Dr. Christopher J. Smiley crystalized in his in-depth analysis of this particular plan, "Benefitting select risk factors while excluding others will play into practitioners' fears that payers are applying risk assessment and evidence-based design simply to control costs."

The ADA has stated that personalized oral care is necessary for good dental health and that patients should "work closely with their dentists to identify any potential risk factors that would determine the need for and frequency of follow up visits to enhance the outcomes of preventive care."

The future may be dominated by individualized risk benefit plans but they must be well grounded in sound scientific method. Capricious implementation of questionable science or the exclusion of well-accepted science diminishes the trust essential to the effective functioning of an oral health care contract encompassing patient, doctor and third-party  payer.

  1. Giannobile WV, Braun TM, Caplis AK, et al. Patient stratification for preventive care in dentistry (published online ahead of print June 10, 2013). J Dent Res 2013;92(8):694-701.
  2. Soderlund K. Delta Dental plan for employees limits cleaning for healthy adults to one per year. ADA News March 2014.
  3. Smiley CJ. Delta Dental's new plan: bringing risk to plan design. J Mich Dent Assoc 2014;96(2):64, 66-67.
  4. Welch HG, Schwartz LM, Woloshin S. Overdiagnosed: Making People Sick in the Pursuit of Health. Boston: Beacon Press; 2012:xii.

Dr. Carney is the editor-in-chief of the Journal of the California Dental Association. Her remarks, reprinted with permission, originally appeared in the October issue of the Journal of the CDA.