The impact of repeat-testing of common chemistry analytes at critical concentrations

Chinelo P. Onyenekwu; Careen L. Hudson; Annalise E. Zemlin; Rajiv T. Erasmus

doi:10.1515/cclm-2014-0331

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The impact of repeat-testing of common chemistry analytes at critical concentrations

Chinelo P. Onyenekwu , Careen L. Hudson , Annalise E. Zemlin and Rajiv T. Erasmus

Published/Copyright: June 18, 2014

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From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 52 Issue 12

Abstract

Background: Early notification of critical values by the clinical laboratory to the treating physician is a requirement for accreditation and is essential for effective patient management. Many laboratories automatically repeat a critical value before reporting it to prevent possible misdiagnosis. Given today’s advanced instrumentation and quality assurance practices, we questioned the validity of this approach. We performed an audit of repeat-testing in our laboratory to assess for significant differences between initial and repeated test results, estimate the delay caused by repeat-testing and to quantify the cost of repeating these assays.

Methods: A retrospective audit of repeat-tests for sodium, potassium, calcium and magnesium in the first quarter of 2013 at Tygerberg Academic Laboratory was conducted. Data on the initial and repeat-test values and the time that they were performed was extracted from our laboratory information system. The Clinical Laboratory Improvement Amendment criteria for allowable error were employed to assess for significant difference between results.

Results: A total of 2308 repeated tests were studied. There was no significant difference in 2291 (99.3%) of the samples. The average delay ranged from 35 min for magnesium to 42 min for sodium and calcium. At least 2.9% of laboratory running costs for the analytes was spent on repeating them.

Conclusions: The practice of repeating a critical test result appears unnecessary as it yields similar results, delays notification to the treating clinician and increases laboratory running costs.

Keywords: audit; critical values; repeat-testing; turnaround time

Corresponding author: Annalise E. Zemlin, MBChB, FCPath (SA) Chem, MMed (Chem Path), Division of Chemical Pathology, National Health Laboratory Service (NHLS), Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg 7505, Parow, South Africa, Phone: +27 21 9384254, Fax: +27 21 9384640, E-mail: azemlin@sun.ac.za

Acknowledgments

The authors are grateful to Dr. M. Rensburg, S. Ratcliffe and Prof. M. Kidd for assistance with the statistical analysis.

Conflict of interest statement

Authors’ conflict of interest disclosure: The authors stated that there are no conflicts of interest regarding the publication of this article.

Research funding: None declared.

Employment or leadership: None declared.

Honorarium: None declared.

References

1. Chima HS, Ramarajan V, Bhansali D. Is it necessary to repeat critical values in the laboratory?: today’s technology may have the answers. Lab Med 2009;40:453–7.10.1309/LMMY883OKBZQQBKUSearch in Google Scholar

2. Kost GJ. Critical limits for urgent clinician notification at US medical centres. J Am Med Assoc 1990;263:704–7.10.1001/jama.1990.03440050098042Search in Google Scholar

3. Toll AD, Liu MJ, Gulati G, Behling EM, Kocher WD. Does routine repeat testing of critical values offer any advantage over single testing? Arch Pathol Lab Med 2011;135:440–4.10.5858/2010-0025-OA.1Search in Google Scholar

4. Lundberg GD. When to panic over abnormal values. MLO Med Lab Obs 1972;4:47–54.Search in Google Scholar

5. Centers for Medicare & Medicaid Services, Department of Health and Human Services. Clinical laboratory improvement amendments of 1988. Fed Regist 2003;1047:68. Codified at 42 CFR 1493.1299(g).Search in Google Scholar

6. College of American Pathologists. Laboratory Accreditation Program. Laboratory general checklist [components GEN.41320, GEN.41330, and GEN.41340]. Available from: http://www.cap.org./apps/docs/pathology_reporting/LabGeneralChecklist_Reporting.pdf. Accessed on 19 September, 2013.Search in Google Scholar

7. The Joint Commission. National patient safety goals effective January 1, 2013. Laboratory Accreditation Program 2013. Available from: http://www.jointcommission.org/assets/1/18/NPSG_Chapter_Jan2013_LAB.pdf. Accessed on 19 September 2013.Search in Google Scholar

8. ISO 15189:2007(E). Medical laboratories – particular requirements for quality and competence.Search in Google Scholar

9. Hashim I A, Cuthbert JA. Establishing, harmonizing and analyzing critical values in a large academic health center. Clin Chem Lab Med 2014;52:1129–35.Search in Google Scholar

10. Kohn KT, Corrigan JM, Donaldson MS. To err is human: building a safer health system. Washington, DC: National Academy Press, 1999.Search in Google Scholar

11. Plebani M. Errors in clinical laboratories or errors in laboratory medicine. Clin Chem Lab Med 2006;44:750–9.10.1515/CCLM.2006.123Search in Google Scholar

12. Dighe AS, Rao A, Coakley AB, Lewandroski KB. Analysis of laboratory critical value reporting at a large academic medical center. Am J Clin Pathol 2006;125:758–64.10.1309/R53XVC2U5CH6TNG8Search in Google Scholar

13. Piva E, Plebani M. From “panic” to “critical” values: which path toward harmonization? Clin Chem Lab Med 2013;51: 2069–71.10.1515/cclm-2013-0459Search in Google Scholar

14. Report of the review of NHS pathology services in England. An independent review for the Department of Health. London: Department of Health, 2006:6.Search in Google Scholar

15. Campbell CA, Horvath AR. Towards harmonisation of critical laboratory result management – Review of literature and survey of Australasian practices. Clin Biochem Rev 2012;33:149–60.Search in Google Scholar

16. Paxton A. Critical value repeats: redundancy, necessity? CAP Today 2010;24:1.Search in Google Scholar

17. Westgard JO. CLIA requirements/tables on CLIA proficiency testing criteria for acceptable analytical performance. Available from: www.westgard.com/clia.htm. Accessed on 14 August, 2013.Search in Google Scholar

18. Eisenman G. Glass electrodes for hydrogen and other cations, principles and practice. New York: Marcel Dekker Inc., 1967:2.Search in Google Scholar

19. Mann CK, Yoe JH. Spectrophotometric determination of magnesium with sodium 1-azo-2-hydroxy-3-(2,4 dimethylcarboxanilido)-naphthalene-1′-(2-hydroxybenzene-5-sulfonate). Anal Chem 1956;28:202–5.10.1021/ac60110a016Search in Google Scholar

20. Gitelman HJ. An improved procedure for the determination of calcium in biochemical specimens. Ana Biochem 1967;18:521–31.10.1016/0003-2697(67)90110-8Search in Google Scholar

21. Zeng R, Wang W, Wang Z. National survey on critical values notification of 599 institutions in China. Clin Chem Lab Med 2013;51:2099–107.10.1515/cclm-2013-0183Search in Google Scholar PubMed

22. Deetz CO, Nolan DK, Scott MG. An examination of the usefulness of repeat testing practices in a large hospital clinical chemistry laboratory. Am J Clin Pathol 2012;137:20–5.10.1309/AJCPWPBF62YGEFORSearch in Google Scholar PubMed

Received: 2014-4-14

Accepted: 2014-5-23

Published Online: 2014-6-18

Published in Print: 2014-12-1

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Articles in the same Issue

https://doi.org/10.1515/cclm-2014-0331

Keywords for this article

audit; critical values; repeat-testing; turnaround time