Onyenekwu C.P., Hudson C.L., Zemlin A.E., Erasmus R.T.
Division of Chemical Pathology, Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg, Parow, South Africa; Department of Clinical Pathology, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
Onyenekwu, C.P., Division of Chemical Pathology, Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg, Parow, South Africa, Department of Clinical Pathology, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria; Hudson, C.L., Division of Chemical Pathology, Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg, Parow, South Africa; Zemlin, A.E., Division of Chemical Pathology, Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg, Parow, South Africa; Erasmus, R.T., Division of Chemical Pathology, Tygerberg Hospital, University of Stellenbosch, PO Box 19113, Tygerberg, Parow, South Africa
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. © by De Gruyter 2014.
calcium; magnesium; potassium; reagent; sodium; calcium; magnesium; potassium; sodium; analytical error; Article; chemical analyzer; cost benefit analysis; health care cost; human; laboratory test; law; medical audit; medical information system; repeat procedure; retrospective study; validity; blood analysis; clinical chemistry; economics; hospital information system; hospital laboratory; reproducibility; statistics and numerical data; unnecessary procedure; Blood Chemical Analysis; Calcium; Clinical Chemistry Tests; Clinical Laboratory Information Systems; Humans; Laboratories, Hospital; Magnesium; Potassium; Reproducibility of Results; Retrospective Studies; Sodium; Unnecessary Procedures