American Society for Clinical Pathology
View all recommendations from this societySeptember 25, 2018
Don’t order IgM antibody serologic studies to assess for acute infection with infectious agents no longer endemic in the US, and in general avoid using IgM antibody serologies to test for acute infection in the absence of sufficient pre-test probability.
As the prevalence of a disease decreases, so does the positive predictive value for testing for acute infection with that disease. Although documentation of IgG antibodies to rare infectious agents is useful (for documentation of effective vaccination, for example), assessing acute infection by evaluation of IgM antibody status to these agents is fraught with false positives and low predictive value. For example, according to CDC, rubella is no longer endemic in the US. As such, nearly all positive rubella IgM antibody tests are false positives, resulting in unnecessary follow-up testing and unnecessary anxiety.
Even for diseases not yet eradicated and for which low level outbreaks still occur (such as measles), if overall prevalence remains low, then the predictive value of positive IgM serology will still be low. False positive measles IgM serology, for example, has been documented due to crossreactivity to parvovirus and human herpes virus 6, among others.
If clinical evaluation yields legitimate pre-test suspicion for a rare infectious disease, then practitioners should report to and engage the help of their state public health department and/or the CDC in further evaluating for potential acute infection.
In common viral infections it is also most effective to limit IgM serology to those cases in which clinical assessment yields relatively high suspicion for acute infection, since there are well known causes for potential IgM antibody cross-reactivity (rheumatoid factor, cross reactivity with other viral antigens). The potential for false positive results will decrease (and positive predictive value will increase) with increasing pre-test probability for true acute infection.
These items are provided solely for informational purposes and are not intended as a substitute for consultation with a medical professional. Patients with any specific questions about the items on this list or their individual situation should consult their physician.
How The List Was Created
1-5: The American Society for Clinical Pathology (ASCP) list was developed under the leadership of the chair of ASCP’s Institute Advisory Committee and Past President of ASCP. Subject matter and test utilization experts across the fields of pathology and laboratory medicine were included in this process for their expertise and guidance. The review panel examined hundreds of options based on both the practice of pathology and evidence available through an extensive review of the literature. The laboratory tests targeted in our recommendations were selected because they are tests that are performed frequently; there is evidence that the test either offers no benefit or is harmful; use of the test is costly and it does not provide higher quality care; and, eliminating it or changing to another test is within the control of the clinician. The final list is not exhaustive (many other tests/procedures were also identified and were also worthy of consideration), but the recommendations, if instituted, would result in higher quality care, lower costs, and more effective use of our laboratory resources and personnel.
6–15: The American Society for Clinical Pathology (ASCP) list of recommendations was developed under the leadership of the ASCP Choosing Wisely Ad Hoc Committee. This committee is chaired by an ASCP Past President and comprises subject matter and test utilization experts across the fields of pathology and laboratory medicine. The committee considered an initial list of possible recommendations compiled as the result of a survey administered to Society members serving on ASCP’s many commissions, committees, and councils. The laboratory tests targeted in our recommendations were selected because they are tests that are performed frequently; there is evidence that the test either offers no benefit or is harmful; use of the test is costly and it does not provide higher quality care; and
eliminating it or changing to another test is within the control of the clinician. Implementation of these recommendations will result in higher quality care, lower costs, and a more effective use of our laboratory resources and personnel.
16-35 The American Society for Clinical Pathology (ASCP) list of recommendations was developed under the leadership of the ASCP Effective Test Utilization Steering Committee. This committee is chaired by an ASCP Past President and is comprised of subject matter and test utilization experts across the fields of pathology and laboratory medicine. The committee considered a list of possible recommendations compiled as the result of a survey administered to Society members serving on ASCP’s many commissions, committees and councils. In addition, an announcement was made to ASCP’s newly formed Advisory Board seeking suggestions for possible recommendations to promote member involvement. The laboratory tests targeted in our recommendations were selected because they are tests that are performed frequently; there is evidence that the test either offers no benefit or is harmful; use of the test is costly and it does not provide higher quality care; and eliminating it or changing to another test is within the control of the clinician. Implementation of these recommendations will result in higher quality care, lower costs and a more effective use of our laboratory resources and personnel.
ASCP’s disclosure and conflict of interest policy can be found at www.ascp.org.
Sources
Binnicker M: Hot topic: Serologic testing for rubella (video presentation with transcript); 2008: http://www.mayomedicallaboratories.com/articles/hottopics/2008-08-rubella.html (accessed 06/21/2017).
Best JM, O’Shea S, Tipples G, Davies N, Al-Khusaiby SM, Krause A, Hesketh LM, Jin L, Enders G: Interpretation of rubella serology in pregnancy—pitfalls and problems. BMJ 2001; 325:147-8.
Dietz V, Rota J, Izurieta H, Carrasco P, Bellini W: The laboratory confirmation of suspected measles cases in settings of low measles transmission: conclusions from the experience in the Americas. Bulletin of the World Health Organization 2004; 82:852-7.
Woods CR: False-positive results for immunoglobulin M serologic results: explanations and examples. J Ped Infect Dis Soc 2013: 2(1):87-90.
