NACB - Scientific Shorts
NACB - Scientific Shorts (formerly NACB Blog)
By Jim Faix, MD
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When I was born (OK, I’ll admit it, it was over a half-century ago), there were about 250 different laboratory tests available for physicians to order. Now, there are probably over 4,000. Certainly, in the intervening years, there have been many new diseases that required new tests for diagnosis, and many new drugs that needed new assays for monitoring therapy. But how many of these 4,000 tests belong in Jurassic Lab, either because they really are “dinosaurs” or because they really are useless? Given the huge problem of the cost of health care delivery, could we help save some money by eliminating tests that are really no longer needed?

 

Three years ago, the editors of CLN asked a number of laboratorians to nominate unnecessary tests. Five were mentioned by the majority of the respondents: the LE cell test; the Schilling test; free thyroxine index; prostatic acid phosphatase; and Bence Jones protein. Eliminating these would probably have little impact on the laboratory’s contribution to health care cost, because they are probably not very frequently ordered. It is similar to the current federal budget battle, where the bulk of the cuts may fall on a small portion of the overall budget because everyone’s afraid to tackle Medicare and the Department of Defense. If we really want to reduce unnecessary tests, let’s discuss whether we really need ANA screening rather than worry about the LE cell test. Forget about prostatic acid phosphatase; is continuing to offer PSA worthwhile?

 

Many new tests are probably much better than old ones. Consider anti-CCP vs. rheumatoid factor, or troponin vs. CK-MB. But do the old ones disappear or do they march on like zombie tests, still ordered by some physicians and still offered by laboratories afraid to say goodbye? At Mayo Clinic, they eliminated CK-MB in 2008 (see the discussion by Amy Saenger and Allan Jaffe in Circulation 118:2200-2206 titled, “Death of a Heavyweight”). Why haven’t we all done so? Some new tests are probably no better than the old ones. And yet, the new tests are often implemented anyway. Do we need assays for antibodies to deamidated gliadin peptide when anti-tissue transglutaminase antibody assays are already extremely sensitive and specific for celiac disease? Do we really need two types of natriuretic peptide assays?

 

I know that there are many aspects to the large expansion of laboratory tests available but wonder if we laboratorians fully understand our role in weeding out the tests that need to go. It is probably not just cost that is a factor. Consider cystatin C vs. creatinine. If cystatin C is a much better marker of glomerular filtration rate, why has it not replaced creatinine? It is easy to say that the reason is cost and convenience. Yet, if cystatin C were as cheap and as widely available as creatinine, how many people think that creatinine would disappear? We need a new paradigm. If a new laboratory test offers no advantages over an existing test, we should treat it like Charley the tuna and say, “Sorry!” But, if it is superior to an existing test, we should replace the existing one. What are your suggestions for candidates for Jurassic Lab?

 

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Posted by
On 4/29/2011

Last 10 years, I moved from clinical pathology at UTMB, Galveston to HIV job position by continued testing infections early with oral materials before Clinical Laboratory Western Blot infection confirmation. Also, I maintained Medscape CME in laboratory medicine and other specialties. Yes, many tests are Jurassic and must be replaced by better tests but I feel CRP should not be eliminated as it continues to be an important health stress test. A friend with neurological condition requested information in super high CRP. My advice was chill out; take it easy to reduce stressful issues. Another friend had high ESR rate but no CRP so physician was unable to determine the problem. With many genetic issues solved, genetic databanks available and health conditions SNPs identified, Clinical labs need new sustainability models. Finally, I just joined linked in and written comments for professionals with disability, biological sciences and now clinical laboratory. Clinical laboratory was last to accept membership. PS - I'm currently unemployed after stroke with hearing loss though now have cochlear implant, I keep to date on scientific, healthcare and clinical lab issues with periodicals from physician friends and our local library. Olapade James, PhD

Posted by
On 3/18/2011

I have published a summary of the tests that our laboratory has discontinued over the past 10 years. http://www.clinlabnavigator.com/Utilization/test-utilization.html Fred Plapp, MD PhD

Posted by
On 3/8/2011

Although it is highly likely that there are various clinical tests that fill this theme, it always troubles me to see a long time proven marker being eliminated. Two cases in point: ALT – blood banks were always anxious to eliminate testing as in their case each test adds to their cost line in their product. ALT was figured to be prime candidate in the late 80’s with the new hepatitis core Ag and Ab tests covering what was considered the need for ALT. Then came the need for maintaining ALT as a Hep C (non A non B) surrogate. Later with the new Hep C tests it was again proposed to eliminate ALT but then the discovery of other Hep Sub groups that tests and “need for testing” were discovered and discussed again keeping ALT in the BB and plasma algorithm. As troubling is the elimination of the western blot for HIV on the horizon. For the past 3 decades the gold standard for HIV confirmation tests has been the Western Blot. The cry from labs has always been what to do with those annoying bands that were present but either did not fit the algorithm or confused diagnosis. Turns out those bands are probably a valuable prognostic and diagnostic indication of other disease states from CFS, to other subtypes of HIV /HTLV not recognized by today’s super specific molecular tests. One could even argue the case in Syphilis RPR testing elimination with the simpler non RPR automated testing, even though the nonspecific RPR positive has been shown to be an prognosticator of certain autoimmune states, like lupus. The fact that these tests that have seen their days limited in terms of their original purpose(utility), and should be replaced by more specific markers, is a good argument. What we may miss in terms of not seeing or understanding in their full utility when research and look back discover the value of “false positive” or non specific result, could someday be a sad wake up call. R Chip Stephens MS

Posted by
On 3/7/2011

Let me give a contrarian point of view. Perhaps, any test, provided it has suitable consistent QC and PT material is still relevant provided it is used properly in a focused and directed application (with good pretest probability indications). For example, an ESR might be the only clue to an underlying disorder especially myeloma or a T3 uptake might still have relevance with the pregnant patient that has difficult to manage thyroid disease. David Alter MD Grand Rapids MI

Posted by
On 3/7/2011

It has been great fun reading comments to this blog post this week. Thanks to all for contributing to the conversation and suggesting other resources such as websites, etc. Another good reference is Wu A et al, Am J Manag Care 2010;16:e220-e227, which studies the decrease in ordering ten candidates for Jurassic Lab, many of which were mentioned in this week's on-line discussion. Jim Faix

About the Author
Jim Faix, MD
Jim Faix, MD  
 
References
 
Outdated Lab Tests
 
Requiem for a Heavy Weight