Rapid diagnostics instrumental to patient care
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Rapid diagnostic tests, now synonymous with COVID-19, are instrumental to patient care, helping to improve antimicrobial therapy, patient outcomes and even infection control, experts said.
“There has been a lot of progress in the last decade looking at more rapid ways to identify patients who have infections,” Romney Humphries, PhD, FIDSA, a professor and director of the division of laboratory medicine at Vanderbilt University Medical Center, told Healio | Infectious Disease News.
Source: Courtesy of Thomas M. File Jr., MD, MSc, MACP, FIDSA, FCCP
We asked Humphries and other experts about the impact that rapid diagnostic tests have had on practice and the barriers to their use, including cost.
“Primarily, viral infections are where we have tools at our fingertips to do very quick diagnostic testing,” Humphries said.
For example, a rapid point-of-care PCR-based platform used for COVID-19 and influenza testing has helped her hospital’s ED rapidly triage patients within 15 minutes during the pandemic.
“We have used [rapid testing] extensively for sorting patients with COVID-19,” said Colleen S. Kraft, MD, MSc, an associate chief medical officer at another facility, Emory University Hospital, and professor of pathology and medicine at Emory University School of Medicine. “We have patients who need surgery, need intervention, and knowing their COVID status has helped us accelerate the next steps of their care.”
Patient care
Most rapid tests are for viral infections because viruses take a long time to grow and culture methods can be less sensitive, which made it necessary to develop molecular-based tests, Humphries said.
“What’s behind a little bit is the bacterial and fungal side of things, where we still rely primarily on culture-based diagnostics,” she said. “That’s an area where there are several days of uncertainty that can be detrimental to patient management.”
Infectious Disease News Editorial Board Member Thomas M. File Jr., MD, MSc, MACP, FIDSA, FCCP, chair of infectious diseases for Summa Health in Akron, Ohio, noted the importance of quickly and correctly diagnosing an infection.
“The faster we can establish the correct diagnosis and provide the best therapy, the better for our patient outcomes,” File said.
Elizabeth S. Dodds Ashley, PharmD, MHS, Infectious Disease News Editorial Board Member and professor of medicine at Duke University School of Medicine, said there are examples “each and every day” of delayed diagnoses harming patients and increasing costs.
“For example, with traditional culturing, where it can take 3 to 4 days for final results, patients often remain on broad-spectrum, empiric therapy until finally the results are known. This increases the individual patient risk for drug toxicities and contributes to overall antimicrobial resistance,” Dodds Ashley said.
In addition to improving patient care, rapid diagnostic tests can also benefit infection control efforts.
Humphries’ hospital uses a broad respiratory viral panel to help cohort patients and avoid outbreaks of illnesses even as basic as the common cold.
“That’s another great place we can use these types of tests,” she said. “Knowing if a patient has an identifiable virus can help from an infection prevention perspective.”
‘Significant’ impact on stewardship
Experts agreed that rapid diagnostic testing can also have a substantial impact on antimicrobial stewardship.
That comes with an array of benefits for patients and hospitals, including more appropriate use and length of antimicrobial therapy, better clinical outcomes, decreased lengths of stay, decreased transmission rates and decreased costs, File said.
“Whenever you’re looking at diagnostic testing and trying to measure the impact on patient care, it can be a little bit difficult because the test in and of itself does not do an action, it provides data that somebody then needs to act on,” Humphries said. “What has been shown time and time again in the literature is that, as these tests are available in a more rapid manner than traditional methods, it makes a significant impact on antimicrobial usage.”
Typically, Humphries said, it is easier to make a clinical decision when testing identifies a more resistant organism than what is currently being covered because “everyone will rapidly escalate.” What is more difficult is getting people to discontinue antibiotics, which typically requires stewardship interventions.
In 2016, researchers estimated that around 30% of antibiotic prescriptions in the U.S. were unnecessary, and that most misused antibiotics are prescribed for viral respiratory conditions.
A study published in 2018 assessed the potential benefits of using rapid molecular respiratory tests in an antimicrobial stewardship program among more than 1,300 inpatients presenting with influenza-like illnesses and found that inappropriate antibiotic use and duration of inappropriate antibiotic use significantly decreased over a 2-year period while the tests were being used in the program.
The study found that, overall, antibiotics were continued inappropriately in 45% of participants despite the detection of a virus, but inappropriate use was much less common in the second year of the study (39.3%) compared with the first (51.3%).
Indeed, Humphries said rapid testing has been particularly successful in identifying infections caused by respiratory viruses.
“For example, in our pediatric facility, when you have kids coming into the emergency room, it may not always be obvious if it’s a viral infection or a bacterial infection, and having more rapid results can help determine the pathway that care is going to take,” she said. “For those instances, respiratory viruses have been a successful story when it comes to rapid testing.”
Beyond respiratory infections
In a video from the 2021 World Anti-Microbial Resistance Congress, Debra A. Goff, PharmD, FCCP, a clinical professor of pharmacy practice and founding member of the antimicrobial stewardship program at The Ohio State University Wexner Medical Center, told Healio | Infectious Disease News that rapid diagnostic tests can improve treatment for sepsis.
“When we look at the time to effective antimicrobial therapy that a rapid diagnostic test can provide, we know that every hour of ineffective therapy in the management of a patient with sepsis translates into mortality,” Goff said.
Humphries said hospitals are starting to integrate some form of rapid diagnostic testing into the management of patients with sepsis.
“You’re talking about shortening the diagnostic uncertainty window by over a day, sometimes 2 days, and so it can really have a huge impact on patient outcomes like mortality,” she said.
In fact, Dodds Ashley said the most compelling data on the impact of rapid testing come from bloodstream infections, “where earlier diagnosis using these technologies has been shown to improve mortality.”
In a 2015 systematic review and meta-analysis, researchers evaluated studies that compared three rapid diagnostic practices with conventional microbiology culture and routine reporting methods. Among the practices, they found that rapid molecular testing combined with direct communication of the test results to clinicians or pharmacists “to immediately confirm targeted therapy or switch patients from broad-spectrum or empirical therapy to targeted therapy ... significantly improves timeliness compared to standard testing.”
‘A national commitment’
In her video, Goff wondered why rapid diagnostic tests were not more widely used in U.S. hospitals.
Sources:
1. CDC.
2. Keske et al.
3. Buehler et al.
“Why are we still accepting the same old same old? Well, sometimes it comes down to the cost, but we have to get past that,” Goff said. “I think we need to create an effective campaign to market time-to-effective antibiotic therapy as life.”
Traditionally, cost has been a barrier to adapting new technologies, Humphries agreed.
“Often, the cost of technology seems daunting and hard to justify in the laboratory budget,” Dodds Ashley said.
A major issue, Humphries said, is budget “silos” — the lab budget is separate from the pharmacy and other patient care budgets.
“When you think of it that way, it can be very difficult to adopt new technology because you’re seeing a huge cost in the lab budget vs. a savings potentially in the pharmacy budget,” Humphries explained. “If they are not working as a team, it can be difficult to show that for the accounting. I hope we’re getting beyond that, although there are certainly still institutions that think that way.”
A solution would require hospitals to “break down traditional silos” in their finances and think about cost at an institutional level, Dodds Ashley said.
“An earlier diagnosis and treatment with increased success shortens hospital stays and has positive impacts on the overall hospital revenue cycle, which can quickly justify the cost of the technology,” she said. “In addition, many of these platforms have multiple tests that can impact many service lines such as stool culture and outpatient respiratory panels that have greater impact on the system.”
Kraft said solving the issue of cost “will take a national commitment.”
“As a hospital executive, we live in a context that we have created with insurance and ordering practices, and it is something that we need to work through and be committed to as patients, providers, health care systems and insurance,” she said.
- References:
- Bouzid D, et al. Clin Microbiol Infect. 2018;doi:10.1016/j.cmi.2020.02.024.
- Buehler SS, et al. Clin Microbiol Rev. 2015;doi:10.1128/CMR.00053-14.
- Fleming-Dutra KE, et al. JAMA. 2016;doi:10.1001/jama.2016.4151.
- Keske S, et al. Eur J Clin Microbiol Infect Dis. 2018;doi:10.1007/s10096-017-3174-6.
- Kilgore M, et al. Am J Infect Control. 2008;doi:10.1016/j.ajic.2008.10.004.
- For more information:
- Elizabeth Dodds Ashley, PharmD, MHS, can be reached at libby.dodds@duke.edu.
- Thomas M. File Jr., MD, MSc, MACP, FIDSA, FCCP, can be reached at filet@summahealth.org.
- Romney Humphries, PhD, FIDSA, can be reached at IDSA@messagepartnersPR.com.
- Colleen S. Kraft, MD, MSc, can be reached at news@emory.edu.
Click here to read the Point/Counter, "Will rapid tests ever fully replace cultures?"
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