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Evaluating overuse of laboratory diagnostics : a case study into diagnosing anaemia in Dutch general practice

Oonk, M.L.J. (2018) Evaluating overuse of laboratory diagnostics : a case study into diagnosing anaemia in Dutch general practice.

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Abstract:Background: Physicians often order laboratory tests of which the results do not contribute to medical decisionmaking. Such unnecessary test ordering is partially caused by uncertainty of physicians about which laboratory tests they need to order. In general practice, many laboratory tests are often ordered simultaneously in diagnosing the underlying cause of anaemia. This study assesses whether each of these tests adds value to this diagnostic process and determines the most efficient subset of tests for (correctly) diagnosing an underlying cause of anaemia. Methods: Logistic regression models were fitted to data about diagnoses established by general practitioners, collected through a previously performed survey including cases of real-world anaemia patients. A stepwise backward selection process was performed: laboratory tests with the lowest added value were iteratively eliminated by selecting subset models, including a subset of the laboratory tests, with the best performance score (Akaike Information Criterion). Results: Eight laboratory tests have a statistically significant impact on diagnosing an underlying cause of anaemia: ferritin, leukocytes, ESR, CRP, reticulocytes, MDRD, folic acid and serum iron. With regard to the correct diagnosis, two tests have a statistically significant impact: ferritin and MCV. The most efficient subset of laboratory tests for diagnosing an underlying cause contains nine laboratory tests: ferritin, CRP, reticulocytes, serum iron, ESR, MDRD, haemoglobin, leukocytes and folic acid. With regard to diagnosing the correct underlying cause, this subset contains five tests: ferritin, CRP, MCV, transferrin and folic acid. Conclusion: Only a subset of the investigated laboratory tests impacts the ability of the general practitioner to (correctly) diagnose an underlying cause of anaemia. Therefore, general practitioners may order the most efficient subset of tests without limiting this ability. Whether such a subset is acceptable and cost-effective in daily practice has to be further investigated. Keywords Diagnostic testing, general practice, anaemia, efficiency, logistic models
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:44 medicine
Programme:Health Sciences MSc (66851)
Link to this item:https://purl.utwente.nl/essays/76876
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