Diagnostic Stewardship: choosing the right test

By the bioMérieux Editors | Reading time: 2 min

PUBLICATION DATE: MAY 22, 2024

Clinical labs are often faced with the challenge of needing to be better, faster, and more productive – while sometimes expected to do so with fewer resources and contending with supply chain issues. With the continued focus on value-based care as a main objective in healthcare, optimizing the utilization of diagnostic testing is more important than ever.

Optimizing utilization includes considerations of overutilization, underutilization, and inappropriate utilization. Institutions must address what shifts in systems, processes, and behaviors are needed to ensure that each considered lab test is utilized only when indicated.

According to Kyle Hueth, Sr. Manager, Global Medical Affairs Scientist at bioMérieux, “Choosing the right test is the first step in diagnostic stewardship, and this critical point in the patient care pathway could spur far-reaching benefits that go beyond a single patient outcome.”

The value of diagnostics in patient care

Recent surveys with specialist clinicians across the USA and Germany confirm the historical notion that nearly three-quarters of clinical decisions depend on laboratory tests (60-70%).¹ However, the ongoing support for laboratory medicine, including proper funding, is usually more influenced by the cost of testing, when the impact on positive patient outcomes should arguably take precedence.

Diagnostic tests are utilized throughout the patient care pathway in three keyways:

Assess the risk of illness. A patient presents at a health care system with infectious disease symptoms, and diagnostic solutions can deliver fast, actionable results that support the initiation of appropriate therapy.
Identify the cause of an infection. Diagnostics and compatible data-driven technology support accurate identification and susceptibly to optimize targeted patient therapy.
Inform/Monitor therapy considerations. Rapid diagnostic solutions can support the appropriate treatment initiation and/or safe discontinuation of antimicrobials, when possible, to avoid potential side effects and the emergence of resistant organisms.

Diagnostic Stewardship: When do you really need a test(s)?

Healthcare spending is under intense scrutiny and overutilization or inappropriate utilization of diagnostic tests can impede the effective use of healthcare funding. It’s estimated that $6.8 billion is spent in the U.S. alone on unnecessary procedures and testing that do not improve care and may even harm patients. Strong diagnostic stewardship is crucial to address this, especially as the complexity of laboratory medicine continues to increase, with the number of laboratory tests available to clinicians more than doubling over the last 20 years.²

While access and utilization of quality diagnostic tests vary across countries, and overutilization may be isolated to individual practitioners, a universal approach to diagnostic stewardship, including collaboration from the laboratory to frontline care is integral.

“If we are to have a measurable impact on patient outcomes associated with the use of diagnostic tests and data, we must employ systems and practices that optimize the utilization of diagnostics to ensure that appropriate testing methodologies are utilized in populations where there is demonstrated efficacy and for which results are available in a time frame to influence clinical-decision making.”

Kyle Hueth, Sr. Manager, Global Medical Affairs Scientist at bioMérieux

While clinicians are often held responsible for determining what tests are needed, patients could benefit from a better understanding of what value individual tests bring to their personal care pathway to support shared decision making.

Together discussions could be had regarding:

What potential impact the test(s) could have on decisions or outcomes?
Would the test provide additional information that is not already available through patient history, exam, or other readily available testing options?
Will the rapidity of results provide influence at the right time?

It is important to note that underutilization of available testing is also critical in diagnostic stewardship. Under testing of possible conditions and pathogens poses risk by limiting a definitive diagnosis that could impact patient care as well as medical costs.

The laboratory can add value to the decision process by applying their skills and knowledge. This may include guiding test selection, advising not to order a particular test, and/or recommending an alternative based on factors such as test accuracy, speed, and proven performance.

This laboratory intervention may occur as individual discussions with providers or, ideally, guidance would be integrated into electronic systems and care pathways to aim for systematic utilization practices. In this way, the laboratory team can be a steward to limit the burden caused by suboptimal diagnostic testing utilization.

Diagnostics Stewardship and Antimicrobial Stewardship Are Complimentary

Antimicrobial resistance (AMR), as explained by the World Health Organization, is a natural process whereby bacteria, viruses, fungi, and parasites can genetically change, becoming no longer responsive to available antimicrobial drugs. However, misuse and overuse of antimicrobials in the treatment, prevention, and control of infectious diseases has accelerated the burden.⁴

Effective implementation of diagnostic stewardship practices helps ensure the right test for the right patient at the right time and when combined with antimicrobial stewardship, leads to the right interpretation to support the right antimicrobial at the right time.³Hueth concludes, “This precise methodology for patient care goes beyond the individual because the collective understanding we gain from the accurate diagnosis and appropriate treatment of individuals in a population, offers key insights into local and global resistance patterns and trends.”

Sikaris KA. Enhancing the Clinical Value of Medical Laboratory Testing. Clin Biochem Rev. 2017;38(3):107-114.
Freedman DB. Towards Better Test Utilization - Strategies to Improve Physician Ordering and Their Impact on Patient Outcomes. EJIFCC. 2015;26(1):15-30. Published 2015 Jan 27.
Hueth KD, Prinzi AM, Timbrook TT. Diagnostic Stewardship as a Team Sport: Interdisciplinary Perspectives on Improved Implementation of Interventions and Effect Measurement. Antibiotics. 2022; 11(2):250. Available at: https://doi.org/10.3390/antibiotics11020250. Accessed January 11, 2024.
World Health Organization. Antimicrobial resistance. Available at: https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance. Published November 21, 2023. Accessed January 11, 2024.