CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
March 2023—Urinalysis was at the heart of a Feb. 7 discussion between CAP TODAY publisher Bob McGonnagle; Ron Jackups Jr., MD, PhD, of Washington University School of Medicine; and Jason Anderson of Sysmex America. “There’s a lot of room to explore what the optimal parameters are to use with the best specificity and sensitivity for a reflex to the sediment analysis or the culture,” Anderson said. Here’s what he and Dr. Jackups said about reflex testing, automation, and middleware.
CAP TODAY’s guide to urinalysis instruments begins here.
Since the urinalysis roundtable in December 2021, three things continue to be hot issues regardless of instrumentation, field of analysis, and subspecialty. Number one is automation in workflow, having something that’s robust for high volume, low staffing. Number two is the need for fit of an instrument line. In other words, there’s a core lab urinalysis instrument that’s ideal and yet there are smaller clinics, hospitals, all kinds of sites that can benefit from the same technology but in a differently configured unit. Number three is understanding if we’re extracting the optimum clinical information from the analysis in fields like hematology and urinalysis.
Dr. Jackups
Ron Jackups, talk to us about reflex testing in urinalysis and then more specifically about what you’ve been working on at Barnes-Jewish Hospital.
Ron Jackups Jr., MD, PhD, associate professor of pathology and immunology, Washington University School of Medicine, and associate chief medical information officer for laboratory informatics, BJC HealthCare: Reflex testing in general has two big benefits. The first is it focuses the diagnostic process, which reduces waste. We have seen in urinalysis and other areas that providers, rather than order a test and wait for the result and then order another test based on that result and wait for the next result, et cetera, tend to do what we call shotgun testing—they order all the tests they think might be relevant at once and then react to the results after they get them. This is wasteful in many situations if the tests further down the line were not necessary and can also be dangerous if one of the tests down the line is a false-positive. Part of the goal of reflex testing is to identify situations where there’s a low diagnostic value and high risk of false-positives in future tests that could be prevented by simply not doing them. That’s the first reason to do reflex testing.
The other benefit, which is smaller but simpler and particularly relates to outpatients, is convenience. You do a single draw of a sample and the patient does not have to be redrawn. If it is an outpatient, they don’t have to come back for a future redraw. Reflexes provide the same kind of turnaround time that shotgun testing would give but without the inconvenience and with a much better diagnostic process.
The impetus for making these reflexes at our institution was what we saw as high false-positive rates of urine cultures, and I don’t mean analytically false-positive. We’re actually diagnosing asymptomatic bacteriuria. Patients who really did not have symptoms of a urinary tract infection but were tested anyway by a urine culture were found to have a positive, and then despite that not being a cause of the patient’s problems, were treated with antibiotics.
This is not only a waste of our antibiotics and a potential trigger of antibiotic-resistant organisms but also a potential financial penalty for the hospital because the Centers for Medicare and Medicaid Services penalizes systems that have a high rate of catheter-associated UTIs [CAUTI]. And if you happen to find an asymptomatic bacteriuria in a patient with a catheter, that counts as a CAUTI and triggers financial penalties as well. That was one of the drivers for making the reflex.
What benefits have you seen?
Dr. Jackups (Wash U): We have seen a dramatic drop, by almost half, in the number of overall urine cultures ordered. The positivity rate on urine cultures has not changed appreciably, which means overall we’re seeing a drop in the number of positive urine cultures but not a drop in the return on urine cultures. It means we’re doing a better job of selecting the patients who are likely to have UTIs.
An outstanding feature of the field of hematology and urinalysis both is how much effort has been devoted to things like urine culture and urinalysis and the manual differential, which is often at excessive numbers in the field of automated hematology because people haven’t properly understood parameters for those analyzers. Sysmex is one of the companies that can work on both sides of this avenue, in urine and hematology.
Jason Anderson, would you agree the parameters aren’t always well understood? And can you speak about general customer recognition and acceptance of improvements made in urinalysis that lead to cost savings and better care?
Jason Anderson, MPH, MT(ASCP), senior product manager, urinalysis solutions, IVD product marketing, Sysmex America: Yes, I agree. One of the many benefits of flow cytometry is that we’re measuring both chemical and physical properties of particles in urine. Our laboratory customers recognize that the accuracy and precision that come with flow cytometry technology means the technology lends itself to high-quality results, which can offer invaluable information in the clinical care pathway for the patients they serve. When it comes down to enumerating particles and using those to make decisions about patient care, whether you’re going to culture or do additional testing, our customers comment positively about and recognize the value of having good-quality, trustworthy results via flow cytometry.
Anderson
Do you have other customers who are as interested in the application of reflex testing in urinalysis as described by Ron?
Jason Anderson (Sysmex): Yes, and I agree with Dr. Jackups’ commentary. With staffing challenges and economic pressures ever present, the need for laboratories to optimize resource utilization, improve turnaround times, and reduce costs, whether it be reagent or labor costs, is becoming increasingly critical. Optimized reflex testing can play an important part in improving those things. Our customers are looking to their in vitro diagnostic vendors and their peers for guidance on reflex testing. Unfortunately there’s not as much evidence-based research as there needs to be in urinalysis for this type of exercise in terms of what the optimal criteria are or the best practice is for reflex testing. I have spoken with clinical investigators who are interested in looking at the performance of certain urine parameters in different populations, whether it’s neonatal, obstetrics, transplant, immunocompromised patients, et cetera. It’s highly likely that it’s not one-size-fits-all criteria for reflex testing; it depends on the population. There’s a lot of room to explore what the optimal parameters are to use with the best specificity and sensitivity for a reflex to the sediment analysis or the culture. Those are important questions that still don’t have definitive answers or answers as good as we need to make better reflex testing decisions.
Ron, urinalysis is not a field that’s rich in research compared with many other areas of the laboratory. But when we talk about reflex testing, I know many CAP TODAY readers have a certain nervousness about ordering their own test. In other words, “We’re determining we’re going to generate more test volume on our own word.” Is that a fairly widespread anxiety?
Dr. Jackups (Wash U): Yes, it is. We do not want to be the people who dictate what tests need to be done on patients. And we need to have some sense of humility because we are not the people in the room seeing the patient, knowing the patient’s problems. Even if we cite clinical research that says otherwise, it’s important to understand clinical research is done on a group of people and the average findings on that group do not necessarily relate to the specific patient in the room at the time. Starting with that humility, it’s important to know that any change we make should not be the sole decision of the laboratory, and these decisions need to be broad policy decisions made with the input of the stakeholders.
When we make these decisions, we have extensive communication with the services that are using the test and with clinical experts who treat patients who have these tests drawn on them. The collaboration we have for urine reflexes is done with an incredible amount of input from and work with the infectious disease experts at our institution, particularly the infection prevention team and the microbiology lab.
Do you go before a certain body to establish that there’s an approved policy in place at Wash U for this sort of reflex testing in urinalysis?
Dr. Jackups (Wash U): We have several governing structures. We created a clinical lab steering committee, which is a group of laboratory leaders that represents the laboratories in the system, and that’s often where these questions get asked. In the course of that discussion we identify the stakeholders outside of the labs who are going to be involved in the discussion. None of these teams by themselves have absolute power to make those decisions. But in coming together and having this consensus and the reputation that we work to improve patient care and reduce waste, we are able to make decisions and get people in the hospital to accept them.
Jason, does this sound familiar to you? Do you have customers trying to do something similar?
Jason Anderson (Sysmex): It does sound familiar and we do. And to Dr. Jackups’ point, no one has absolute decision-making power here. It falls to the laboratory in conjunction with its medical director and clinician staff to decide what’s appropriate for their patient populations when determining and employing reflex testing algorithms in the test menu. One of the things that plagues urinalysis is there are not a lot of clearly defined best practices when it comes to how to report and interpret some urine parameters. What are the best units in which to report a specific urine particle? Is semiquantitative high power field/low power field range reporting for particles ideal or can we better take advantage of improved technology that can return a specific value for particles such as red and white blood cells? There is not a lot of strong, concrete evidence and scientific study yet surrounding questions like these. It opens things up to questions: What are the parameters of choice? Where do the specificity and sensitivity need to lie to make these reflex decisions to meet the greater good of the population and provide the best patient care? Investigators are beginning to think about these aspects more, and we hope to see exciting research in the near future that can give laboratories a jumping-off point to make better decisions on when to reflex.
To Dr. Jackups’ point, the clinician needs to be able to make the best decision for their patient in terms of test orders. Reflex testing can help laboratories with optimizing utilization, which can significantly impact turnaround times. If a laboratory is performing unnecessary testing—testing that would not have been performed if governed by optimal reflex test criteria—then it is spending time and resources that could be used for other, more value-added tasks.