NEW YORK (GenomeWeb) – A new study comparing the BD Max enteric bacterial panel, or EBP, to traditional stool culture has shown the Becton Dickinson panel can result in significant savings.
In the study, published last month in BMC Clinical Pathology, researchers measured 86 samples, assessing turnaround time, total cost, as well as impact on lab processes for the five infectious pathogens that cause up to 95 percent of acute bacterial gastroenteritis.
The researchers measured elapsed time from specimen log in to actionable results. They also quantified the number of clinical decisions and steps required during processing, and the total distance traveled in the lab by 11 different lab techs running the assays.
First author on the study Joel Mortensen, director of the diagnostic disease testing laboratories at Cincinnati Children's Hospital, told GenomeWeb in an interview that he was previously part of a multi-center evaluation of the EBP, but wanted to bring scientific rigor to a natural follow-up question: "What does the next step look like as we operationalize this new technology?"
The BMC study showed that running the EBP reduced turnaround time from around 44 to about seven hours. The authors also used time-motion analysis, showing the 'spaghetti diagram' of the movement paths required for culture versus EBP was more convoluted. They further determined that technologists were required to make 82 percent fewer decisions using the EBP.
The study found that stool culture cost between $26.06 and $64.30 per sample, while EBP cost $32.19 to $37.44.
"I can do the BD Max on a stool sample cheaper than I can do a routine stool culture in the traditional sense, provide it in a timely fashion, and allow it to be focused on the actual clinical need," said Mortensen, who is also a professor in the department of pathology and laboratory medicine at the University of Cincinnati.
The lab is now in the final stages of validating the platform and expects to "phase out the majority of the material and labor required for routine bacterial stool culture … replacing that routine bench [set up] with the BD Max" in the next few weeks.
Anticipating the approval of additional stool panels for parasites and viruses, the lab will likely phase out stool culture completely in the next year, Mortensen said, and refocus staff on things like molecular antibiotic resistance testing.
Adopting the BD Max EBP means the lab will also need fewer refrigerators, incubators, and hoods, and less of the traditional clinical lab equipment and reagents.
"Because of our move toward BD Max and some MALDI-TOF, we've reduced our number of store room orders — different kinds of kits, tests, and materials — by at least 10 percent so far, and we’re shooting for 25 percent," Moretensen noted.
The Cincinnati Children's clinical lab will for the near future maintain stool culture capacities for specialized applications, he said. "Ask me what it looks like in five years, I don't necessarily know, but for the next five years we will continue to have the expertise and technology if there are individual and unique cases that require it."
Thoughts on panel size
Labs adopting multiplex molecular panels for infectious disease diagnosis are currently faced with a choice between narrow and broad varieties.
As previously reported, Becton Dickinson has gone the route of developing separate bacterial, parasite, and viral panels for gastrointestinal pathogens, while firms like BioFire and Nanosphere combine these pathogens into a more "shotgun" test.
Some in the industry are strong advocates of the broad syndromic approach. Christine Ginocchio, vice president of global microbiology affairs at BioMérieux, recently told GenomeWeb that comprehensive GI panels are picking up more cases and revealing important data on asymptomatic carriage.
Some end users, like Paul Schreckenberger, director of the clinical microbiology laboratory at Loyola Medicine, might even be called opposed to more narrow panels.
Mortensen, meanwhile, suggested that narrow and broad panels could ultimately have complimentary roles.
"Panel selection really has to do with your clinical needs," Mortensen explained. Patients who are immunocompromised or have had a small bowel transplant, for instance, could perhaps benefit from "a very large panel of tests that have a very high cost, [and] higher labor," he said.
"That's much different from your everyday stool culture needs; [those] have very clear guidelines from a variety of national clinical organizations, and I think allow one to focus more clearly on a request for bacterial pathogens in a cost effective timely fashion."
Furthermore, extensive and comprehensive panels "may be billing for tests not requested, or potentially generating results that were not in the original clinician's request," Mortensen said.
The medical and legal implications of having a verified lab result a clinician did not request, which the lab must then decide whether or not to report, makes Mortensen uncomfortable.
"Some vendors are now saying, 'We are going to give you the opportunity to turn off, test by test, some of these results,' so the machine may know it but you won't know it, so you won't have to feel obligated to report it," he said. "But you still have to pay for the reagents to do that test; that's sort of painful."