What is a minimum retesting interval?

A minimum retesting interval (MRI) is the minimum time before a test should be repeated. A relatively recent addition to the test utilization toolbox, MRI is based on a test’s properties such as analytical characteristics and biomarker half-life, as well as the clinical context in which the test is used.

Implementing MRI reduces hospital-acquired anemia, risk of injury, pain, anxiety, sleep disruption, the need for transfusions, length of hospital stay, and even mortality. By reducing oversampling artifacts, using MRI can decrease false alerts, thus cutting down on unnecessary subsequent workups.

It also can help institutions cut back on “low-value” tests, such as routine blood work performed on stable inpatients, which rarely yields intervention-worthy results when repeated. This is significant because such low-value testing diverts personnel, materials, time, and money away from high-value testing. Additionally, implementing MRI can reduce biomedical waste, as more than a third of the volume of diagnostic blood samples is usually discarded, along with contaminated disposables.

What interventions are most useful for getting practitioners to implement MRI?

The three major types of interventions are: educational efforts, changes in computerized physician order entry (CPOE), and audit and feedback (A&F) interventions. These approaches often are combined.

Educational efforts might include presentations, seminars, flyers, and emails. Relevant information could be relayed or distributed at team discussions or rounds, for example, or through guidelines, standard operating procedures, and algorithms. Materials might note the test’s cost and projections of healthcare savings associated with using MRI.

Integrating MRI alerts and rules into CPOE is the most directly actionable approach. A computerized decision support system in the CPOE provides an optimal intervention opportunity because it is specific to a given clinical scenario.

CPOE interventions may include soft- or hard-stop interventions such as alerts, pop-ups, rejection rules, cost displays, order-form modifications, and more.

A&F approaches could come in the form of weekly and monthly reminder letters following educational efforts or feedback on an individual’s ordering habits relative to peers.

No matter which intervention is used, obtaining buy-in from all stakeholders increases the likelihood of success. Laboratory stewardship committees should include representatives from the hospital administration, clinics, and laboratories. It's also important to involve residents and junior physicians.

What are some hurdles to implementing MRI?

Many clinicians either don’t know about MRI or react defensively when asked to use it. Educational efforts could help address these obstacles, but such initiatives require a lot of effort. Automating intervention through CPOE is the most effective approach, but it’s also labor intensive, as it involves modifying order sets, suggesting new order forms, or instating time limits.

As for A&F interventions, it can be difficult to determine the best frequency for reminders and to ensure consistent follow-through on feedback.

Another roadblock is a lack of strong scientific evidence to convince ordering practitioners to implement MRI. Because there is a large degree of variability in study designs, test utilization principles applied, test parameters, and clinical outcomes evaluated, even meta-analyses of the data are hard to find. Moreover, there is little research on the sustainability of implementation programs. There are differences among guidelines about MRI for the same target parameters, and very few studies have looked at the relationship between reduced testing and missed diagnoses.

Finally, since paper medical forms are still used in many parts of the world, a lack of medical-record integration also poses a challenge to implementation.

Asmita Hazra, MD, is an assistant professor of biochemistry at the All India Institute of Medical Sciences, Kalyani in Kalyani, India. She is also chair-elect of the AACC India Section. +Email: [email protected]