Appropriateness of Lime Appropriateness of Lime Disease TestingDisease Testing

Article by Alan H. Ramsey, MDArticle by Alan H. Ramsey, MDEdward A. Belongia, MDEdward A. Belongia, MDPo-Huang Chyou, PhDPo-Huang Chyou, PhD

Jeffrey P. DavisJeffrey P. Davis

Presented by

Summary of IntroductionSummary of Introduction Lyme Disease is a multisystem tick-borne Lyme Disease is a multisystem tick-borne

infection caused by the spirochete Brrelia infection caused by the spirochete Brrelia burgdorferi. One infected a person can burgdorferi. One infected a person can experience Erythematic migran, or expanding experience Erythematic migran, or expanding rashes. rashes.

Some other symptoms of Lyme Disease Some other symptoms of Lyme Disease include joint, neurological, cardiac and other include joint, neurological, cardiac and other manifestations(Wikipedia,2006). manifestations(Wikipedia,2006).

One way of diagnosing Lyme Disease is when One way of diagnosing Lyme Disease is when there is an absence of antibodies to combat there is an absence of antibodies to combat Lyme Disease Lyme Disease

2.8 million Lyme Disease serological tests are 2.8 million Lyme Disease serological tests are performed each year in the United States, with performed each year in the United States, with a cost of $40 per testa cost of $40 per test

““Any of several laboratory procedures carried Any of several laboratory procedures carried out on a sample of blood serum, the clear out on a sample of blood serum, the clear liquid that separates from the blood when it is liquid that separates from the blood when it is allowed to clot. The purpose of such a test is allowed to clot. The purpose of such a test is to detect serum antibodies or antibody-like to detect serum antibodies or antibody-like substances that appear specifically in substances that appear specifically in association with certain diseases.”(Enyclopedia association with certain diseases.”(Enyclopedia Brittanica,2007)Brittanica,2007)

Summary of Introduction IISummary of Introduction II There is a concern that these serological tests are used There is a concern that these serological tests are used

inappropriately by clinicians. inappropriately by clinicians. Early testing based on only tick bites or potential exposure to ticks Early testing based on only tick bites or potential exposure to ticks

has low sensitivity and specificity. (NOT RECOMMENDED)has low sensitivity and specificity. (NOT RECOMMENDED) For patients that live in areas where Lyme Disease is a growing For patients that live in areas where Lyme Disease is a growing

problem, and have patients with erythma migrans, serologic testing problem, and have patients with erythma migrans, serologic testing is not recommended, because the likelihood that these patients is not recommended, because the likelihood that these patients have Lyme disease goes past the positive predictive value of have Lyme disease goes past the positive predictive value of serologic testing, and the negative predictive value of serological serologic testing, and the negative predictive value of serological testing is really low.testing is really low.

To find out the factors that contribute to appropriate and To find out the factors that contribute to appropriate and inappropriate use of Lime Disease Serological Testing, doctors inappropriate use of Lime Disease Serological Testing, doctors conduct a cross sectional survey of clinicians that carry out Lime conduct a cross sectional survey of clinicians that carry out Lime Disease serological testingDisease serological testing

Summary of the MethodsSummary of the Methods The Doctors carried out a survey, by surveying the clinicians who The Doctors carried out a survey, by surveying the clinicians who

submitted specimens for an LDST to 2 large laboratories in submitted specimens for an LDST to 2 large laboratories in Wisconsin. Wisconsin.

Up to 30 tests per month were selected from each laboratory during Up to 30 tests per month were selected from each laboratory during October 1999 to September 2000. October 1999 to September 2000.

Only 2 tests per clinicians were sampled during each studyOnly 2 tests per clinicians were sampled during each study Then each clinician was given access to medical records and told to Then each clinician was given access to medical records and told to

complete a standardized survey by phone. complete a standardized survey by phone. The data collected pertained to the clinician characteristics and The data collected pertained to the clinician characteristics and

clinical circumstances related to each of the testsclinical circumstances related to each of the tests Each test was then classified into appropriate, inappropriate or Each test was then classified into appropriate, inappropriate or

discretionary using clinical principlesdiscretionary using clinical principles A test was defined Appropriate if the patient had any objective A test was defined Appropriate if the patient had any objective

findings consistent with various symptoms that include joint, findings consistent with various symptoms that include joint, neurological, or cardiac symptoms. Such as arthritis, lymphocytic neurological, or cardiac symptoms. Such as arthritis, lymphocytic meningitis, cranial neuritis, or atrioventricular conduction defects. meningitis, cranial neuritis, or atrioventricular conduction defects.

Summary of Methods IISummary of Methods II A test was innapropriate if A test was innapropriate if

the patient was showing no the patient was showing no signs of disease, was treated signs of disease, was treated experimentally with experimentally with antibiotics, or the test was antibiotics, or the test was ordered as a test of cure. ordered as a test of cure.

Because evidence based Because evidence based practice guidelines do not practice guidelines do not address Lyme Disease address Lyme Disease testing for other symptoms testing for other symptoms like fatigue or malaise, the like fatigue or malaise, the test was defined as test was defined as discretionary if it met none discretionary if it met none of the criteriaof the criteria

“Enzyme-Linked Immuno Sorbent Assay a serological test in which the sensitivity of the reaction is increased by attaching an enzyme that produces a colored product to one of the reactants (multi-well ELISA plate; wells showing yellow color are positive)”(Apsnet,2006)

Table of Appropriate and Inappropriate Table of Appropriate and Inappropriate Indications for an LDST, Lyme-Endemic Indications for an LDST, Lyme-Endemic

RegionRegion

Patient with carditis

Serologic test ordered as a test of cure

Patient with atrioventricular block

Patient treated experimentally with antibiotics

Patient with lymphocytic meningitis

Patient with clinician-diagnosed erythma migrans

Patient with cranial neuritis

Patient is asymptomaticPatient with arthritisInappropriateAppropriate

Summary of Results Summary of Results

The Doctor’s sampled 408 LDST requests and The Doctor’s sampled 408 LDST requests and 356 surveys were completed, 250 clinicians 356 surveys were completed, 250 clinicians completed only 1 questionnaire, and forty completed only 1 questionnaire, and forty clinicians refused to participate, and 12 could clinicians refused to participate, and 12 could not be reachednot be reached

Of the 356 LDST requests, 20% were classified Of the 356 LDST requests, 20% were classified as appropriate, 27% appropriate and 53% as appropriate, 27% appropriate and 53% discreinary. discreinary.

The reasons for classifying tests as inappropriate The reasons for classifying tests as inappropriate included absence of symptoms(55%), empirical included absence of symptoms(55%), empirical antibiotic treatment(27%), test of cure(27%), antibiotic treatment(27%), test of cure(27%), and diagnosis of erythma migrans(24%)and diagnosis of erythma migrans(24%)

Summary of Results IISummary of Results II Patient-initiated tests were more likely to be inappropriate than Patient-initiated tests were more likely to be inappropriate than

tests initiated by clinicianstests initiated by clinicians Two factors were independently associated with inappropriate Two factors were independently associated with inappropriate

testing: Known or suspected tick bite within 30 days of illness onset, testing: Known or suspected tick bite within 30 days of illness onset, and test ordered by an emergency or urgent care clinician.and test ordered by an emergency or urgent care clinician.

In this study more than 50% of the inappropriate tests were for In this study more than 50% of the inappropriate tests were for asymptomatic patients.asymptomatic patients.

Compared with family physicians, and internists, physcians in Compared with family physicians, and internists, physcians in emergency or urgent care were more likely to order inappropriate emergency or urgent care were more likely to order inappropriate tests. The Doctors speculated that the people that ordered the tests tests. The Doctors speculated that the people that ordered the tests were not educated enough.were not educated enough.

Interventions should be focused on educating providers about Interventions should be focused on educating providers about indications for Lyme disease testing, mainly about the absence of indications for Lyme disease testing, mainly about the absence of symptoms with or without a tick bite to eliminate the need for symptoms with or without a tick bite to eliminate the need for testingtesting

Summary of Results IIISummary of Results III

The Doctors also found out that patients The Doctors also found out that patients requested a lot of number of tests, that requested a lot of number of tests, that turned out to be innappropriate(40%), turned out to be innappropriate(40%), although most of the inappropriate tests although most of the inappropriate tests were carried out by physicians.were carried out by physicians.

A limitation of the study was that clinical A limitation of the study was that clinical information was provided by clinicans information was provided by clinicans without validation of medical record without validation of medical record reviewreview

ConclusionConclusion

The Doctors concluded that inappropriate The Doctors concluded that inappropriate Lyme Disease serologic testing was Lyme Disease serologic testing was common in Wisconsin, and patients common in Wisconsin, and patients initiated many of these tests.initiated many of these tests.

Expanded Education for clinicians and Expanded Education for clinicians and patients about testing indications may patients about testing indications may reduce the number of inappropriate LDST reduce the number of inappropriate LDST requests.requests.

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