Study Claiming Over-Testing for Lyme Is Disputed

Expert contends they're not done often enough

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By
HealthDay Reporter

FRIDAY, Aug. 6, 2004 (HealthDayNews) -- The debate over how much testing for Lyme disease is too much has turned up in the pages of a medical journal.

A study in the July/August issue of the Annals of Family Medicine claimed that doctors order too many inappropriate tests for Lyme disease, often just giving in to the demands of worried patients.

But a letter just published on the journal's Web site questions the validity of the study, saying that the researchers used too narrow a definition of Lyme disease, downplayed the fact that the test itself is flawed, and didn't treat the illness as a serious enough one to merit a certain percentage of negative test results.

Study author Dr. Alan H. Ramsey, an assistant clinical professor of family medicine from the University of Wisconsin, said his team concluded "a good number of Lyme disease blood tests are ordered inappropriately, primarily for patients who come in without symptoms."

But a Lyme disease expert said Ramsey's group focused only on the early, easily recognizable symptoms, such as a bulls-eye red rash and joint pain, and ignored the less tangible symptoms of the disease that can follow a missed diagnosis. These include cognitive problems, generalized pain and chronic fatigue.

"They [Ramsey's group] used a very narrow definition for Lyme disease, so narrow that you would be guaranteed to get a significant number of inappropriate tests," said Dr. Raphael B. Stricker, a co-author of the rebuttal letter and president-elect of the International Lyme Associated Disease Society.

"All they were looking at is the acute manifestations, which you don't see that much," he said. "They are excluding the majority of patients with Lyme disease for whom testing would be appropriate. But according to their parameters, it's not."

However, Ramsey stands by the results.

"Dr. Stricker fails to acknowledge in his letter that we found the majority of tests to be discretionary, that is, of indeterminate appropriateness using existing guidelines," he said. In the study, Ramsey's team found 27 percent of the tests were possibly inappropriate.

"It was only 27 percent," Stricker replied. "If you consider Lyme disease a trivial illness, then 27 percent of inappropriate tests is probably a big number."

However, Stricker said he considers Lyme disease a significant illness, akin to syphilis or AIDS.

"In AIDS, if you do voluntary testing, the positive rate is about 2 percent or less, so you could argue that 98 percent of those tests are inappropriate," Stricker said. "Does that mean we shouldn't be doing those tests? I don't think anyone would argue that."

The same is true for syphilis, Stricker noted, where you have to test a lot of people to find one positive case.

There is a double standard, Stricker added: "A trivial illness like Lyme disease, it's not important to test. But syphilis or AIDS, oh boy, you better test people because it's a really serious illness."

"Their data suggests that they did the study the wrong way, and that the data is meaningless," Stricker said.

"Dr. Stricker puts words in our collective mouths," Ramsey said. "We never declared Lyme disease to be a trivial illness that is 'hard to catch and easy to cure.' These are his words. Nonetheless, in outlining our second major error, Dr. Stricker confuses test appropriateness with validity."

Stricker said that most of the so-called inappropriate tests were done in emergency rooms. "You don't go to an emergency room because you're asymptomatic," he said.

"As a practicing emergency physician, I can assure Dr. Stricker that asymptomatic patients are often evaluated in the emergency department," Ramsey said. "For example, we found that a known or suspected tick bite was strongly associated with inappropriate Lyme disease testing."

"Anyone who thinks they may have Lyme disease should be tested. They need to be tested," Stricker said.

Stricker and Ramsey agree there are problems with the current Lyme disease test. According to Stricker, unless the test is done at a very good lab, 50 percent of the cases of Lyme disease can be missed.

"We agree with Dr. Stricker that Lyme disease serologic tests remain flawed," Ramsey said. "Indeed, this fact forms the foundation of our study. It is our hope that clinicians find the results of this study helpful in using existing Lyme disease serologic tests more effectively."

Roughly 2.8 million tests for Lyme disease are given each year, carrying a price tag of $100 million annually. Antibiotics are the standard treatment for the disease.

More information

The National Library of Medicine has plenty of information about Lyme disease.

SOURCES: Raphael B. Stricker, M.D., California Pacific Medical Center, San Francisco, and president-elect, International Lyme Associated Disease Society; Alan H. Ramsey, M.D., M.P.H., assistant clinical professor, family medicine, University of Wisconsin, Madison; July 28, 2004, Annals of Family Medicine; Aug. 3, 2004, Annals of Family Medicine online

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