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Appropriateness of laboratory testing

Giuseppe Lippi
MD
Associate Professor of Clinical Biochemistry
Sezione di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico-Biomediche,
Università degli Studi di Verona
Ospedale Policlinico G.B. Rossi
Verona, Italy

Roberto Fostini
Senior Assistant
Medical Direction
Dirigenza Medica
Azienda Ospedaliera di Verona
Italy

Appropriate utilisation of laboratory resources is a cornerstone of medical practice. Although ­laboratory tests are ordered on a rather heterogeneous basis, there is strong ­evidence that laboratory testing may be inappropriately requested, producing adverse clinical and ­economic outcomes for the patient and the entire healthcare system. These problems should not be overlooked, and rational interventions are urgently needed by combining solutions at different levels, developied through specific changes to the environment in which tests are ordered.

In the age of evidence-based medicine, results of laboratory testing are integral to clinical decision-making. Revolutionary technical innovations and emerging diagnostic challenges such as genomics, proteomics and bioinformatics, along with increased test complexity and wedging pressure from costcontainment and reimbursement policies, have forced clinical laboratories to reorganise on a constant basis.(1) Achieving a high degree of innovation, efficiency and throughput with little influence on the ­quality of the total testing process will become the primary goal for laboratory medicine in the future. The cost-to-benefit ratio of laboratory diagnostics mainly develops through a discretional and appropriate utilisation of diagnostic testing. Accordingly, increased laboratory use is appropriate only if it allows accurate ­diagnoses to be made, ideal treatment to be identified and monitored, accurate prognoses to be ­established and patients’ hospital stays to be shortened. Unfortunately, the considerable ­diagnostic armamentarium currently available has been associated with considerable but often inappropriate ­utilisation.

The testing process
The overall testing process develops through Lundberg’s brain-to-brain turnaround time loop, which ideally begins with a clinical hypothesis coming from the physician’s brain and the selection of the most ­appropriate examinations to support clinical decision-making (see Figure 1).(2) Although laboratory tests are ordered on a heterogeneous basis, varying from none to constant monitoring of all variables, the inappropriate utilisation of laboratory resources is commonplace and is characterised by redundancy, ­attitude to ­prescribe by “broad profiles”, improper utilisation, lack of familiarity with innovative tests or simple uncertainty. A comprehensive analysis estimates that 5–95% of the analyses performed daily in ­clinical ­laboratories may be inappropriate,(3) confirming that conveying diagnostic hypotheses to laboratory ­testing is still a challenging process. Redundancy (ie, tests that are repeated too early to provide clinically useful information) is a minor issue that can be easily addressed through simple educational interventions to increase surveillance. The main problem, which appears to be cultural, is the large amount of unnecessary tests requested because of ­inexperience or lack of knowledge.(3)

[[HHE07_fig1_L15]]

Inappropriate testing has potential negative consequences both for the patient and the healthcare system. Abnormal results from unnecessary testing are not ­uncommon. The current definition of reference ranges is based, for most parameters, on a statistical approach comparing predetermined interpercentile intervals (generally the 2.5° and the 97.5° percentile ­limits) with the reference population.(4) In spite of the probability of unmasking silent or asymptomatic disorders, generation of “outnormal” values may be occasionally associated with an increased likelihood of false-positive results, cascade of further unnecessary testing, fear, anxiety and discomfort for the patient, and a contextual unjustified inflation of the associated costs.(3)

Some reliable solutions can be adopted to influence physicians’ test-ordering behaviour. Efforts to develop consensus, traditional educational methods, use of audits and presentation of laboratory charges are generally unproductive, especially when implemented separately.(5) Therefore, an integrated combination of solutions at different levels is expected to generate more favourable revenues, especially in the long term. This strategy includes implementation of clinical guidelines and best-expert clinical opinion at local level, redesign of laboratory test order forms, peer management and broad implementation of information technology by computerised order entry systems and specific reminders or checks of redundancy on the test report. Formulation of clinical queries (rather than simple test requests by physicians) and interpretative comments added to clinical reports would also support this process. Furthermore, the laboratory community should provide guidance on the right use of innovative tests within the diagnostic framework, preferably in accordance with validated guidelines.(6) The selection of clinically relevant, cost-effective technologies and testing protocols that effectively contributes to earlier diagnosis and better disease management is a pivotal prerequisite to allow the cost-effective utilisation of laboratory services.

Conclusion
Due to continuous changes in organisation, as well as the number and types of tests, the inappropriate use of laboratory resources is expected to grow in the near future, using up economic resources and adversely impacting patient care.(3,5) Reliable strategies are needed to prevent these unnecessary expenditures from increasing the economic crisis in several healthcare systems. They should complement efforts already underway in most laboratories to reduce the unit-cost of testing. Specific changes to the environment in which tests are ordered hold considerable promises in convincing clinicians to review their prescribing practices and in disclosing problems in other areas of healthcare.

References

  1. Plebani M. The future of clinical laboratories: more testing or knowledge services? Clin Chem Lab Med 2005;43:893-6.
  2. Lundberg GD. How clinicians should use the diagnostic laboratory in a changing medical world. Clin Chim Acta 1999;280:3-11.
  3. van Walraven C, Naylor CD. Do we know what inappropriate laboratory utilization is? A systematic review of laboratory clinical audits. JAMA 1998;280:550-8.
  4. Guidi GC, Lippi G, Solero GP, Poli G, Plebani M. Managing transferability of laboratory data. Clin Chim Acta 2006;374:57-62.
  5. Neilson EG, et al. The impact of peer management on test-ordering behaviour. Ann Intern Med 2004;141:196-204.
  6. Lewandrowski K. Managing utilization of new diagnostic tests. Clin Leadersh Manag Rev 2003;17:318-24.
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