Choosing New Diagnostics for the Dental Office

Marjorie Jeffcoat, DMD


March 09, 2012

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Hello. I am Dr. Marjorie Jeffcoat from the University of Pennsylvania. Today, I will be talking about new diagnostics in the dental office and posing the question: When do we use them? Every week when we read journals or the dental news, or attend a dental meeting, we hear about some new diagnostic test, usually a saliva test.

We need to think about how we would assess a test to decide whether we want to put it in our office. In my opinion, you don't put a new test in your office unless it's going to make a difference to your diagnosis or treatment. You should go through 5 steps in evaluating a new test.

First, will the results of the test make a difference to treatment? If not, don't use it.

Second, is the test accurate in diagnosing what it purports to diagnose? The ability to detect disease when it exists is called "sensitivity," and the ability to rule out disease when it is absent is termed "specificity."

For example, let's say we have a new test for squamous cell carcinoma, which we all know we would rather not see in our patients. We want to diagnose it quickly and begin the right treatment quickly. A test that has high sensitivity and lower specificity is useful, even though the test is not perfect. We would like all tests to be perfect, but in a real world that doesn't happen.

High sensitivity and low specificity means you may think you have disease sometimes when it is not there. Some patients will get a biopsy when they did not, in fact, have the disease. In my opinion, a biopsy is a very small price to pay for an accurate diagnosis of a deadly cancer. The package insert is very useful for this information. The package inserts are usually on the Web as well.

Third, you want to know if the results are repeatable. Do you get the same result over and over again if you test the same thing? It must be repeatable. That information is also in the package insert.

Fourth, you want to know if the test is available. By "available," I don't mean whether you can buy it on the corner in the drugstore, but rather, if the test breaks, can it be fixed? Some tests incorporate a robot that dips a strip into liquid and then into another liquid. What if it breaks? Who can fix it? Where are the parts? How long will it be out of service if it breaks? You need to consider availability.

Finally, you should consider affordability. Affordability is in the eye of the beholder because each practice is going to make an individual decision. But we need to know if the test covered by insurance. If not, will the patient pay for it? How will the dentist be reimbursed? These are increasingly complicated issues, and they are only going to get more complicated as time goes on.

In summary, before you decide to adopt a new diagnostic test, you need to assure yourself that it's good enough, reliable enough, and available enough to make a difference in how you will treat or refer patients. Otherwise, you just don't need it.

That's it for today. I'm Marjorie Jeffcoat speaking from the University of Pennsylvania. Thanks for watching.

Web Resources

Rao G. Remembering the meanings of sensitivity, specificity, and predictive values. J Fam Pract. 2004;53:53. Accessed March 2, 2012.


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