College of American Pathologists

  Feature Story


cap today

Expert systems a feast for leaner laboratories

January 2002
Karen Southwick

By this spring, laboratorians at St.Vincent Health System, Little Rock, Ark., will be able to glance at a computer screen to see whether a venipuncture that is stat or timed is overdue. The machine will flag any test that is approaching overdue.

In Baton Rouge, La., a computerized system at Our Lady of the Lake Medical Center monitors results of hepatitis panels and delivers interpretations to the requesting physicians.

When ACM Medical Laboratory, Rochester, NY, runs a specimen from a dialysis patient, the laboratory system automatically adds "pre-dialysis" or "post-dialysis" to the bar-code label to prevent a mixup.

So-called expert systems, which as part of a laboratory or hospital information system respond to programmed rules governing how and when lab tests are run, are finding more use in these days of tight budgets and resource constraints. Although resistance remains to allowing a machine to take over tasks once reserved for technologists or pathologists, that resistance is waning, thanks to more sophisticated systems and a better understanding of how to use them.

Responding to clients’ needs

One area where hospital-based and reference labs make extensive use of expert technology is in delivering results to their clients in the requested manner. In the past, if a physician’s office wanted, say, stat results delivered immediately by phone and all other results faxed daily at 4 PM, laboratory staff would have to commit those preferences to memory. Today, expert systems do everything from popping up a reminder message on a callback screen to automatically faxing hundreds of results.

Physician offices that contract for laboratory work with Arnot Ogden Medical Center, Elmira, NY, can receive results in several ways. "We can fax them all the lab results, just the critical results or just the stats, or other designated kinds of tests," says Boyd Wilson, MD, medical director of the laboratory.

Physicians with patients on anticoagulants may want prothrombin time results faxed immediately, he says. A group of obstetricians who do fertility testing prefer to receive all hormone levels at a certain time each day. Transplant centers served by the laboratory get all their patients’ test results faxed immediately. "The Arnot has used this type of logic for a number of years with our McKessonHBOCPathLab system," says Dr. Wilson. "Now we are in the process of building similar rules into our new SIA Molis system. By having the computer check results against the client name and respond to their faxing criteria, it eliminates a lot of the manual labor that the techs used to do and the errors associated with a manual system."

Alliance Lab Services, part of the Health Alliance of Greater Cincinnati, serves five hospitals, as well as outpatient centers, 80 nursing homes, physician offices, and pharmacies. Physicians can receive their results by fax or online every hour, or as soon as lab tests are completed, or at designated times of day. Within the hospitals, results are delivered electronically via the hospital information system and printed automatically if they’re urgent. Alliance’s expert technology is supplied by McKesson’s Horizon Lab, says Joanne Griffith, executive director of laboratory services. Pharmacies also access results online or get a fax of daily values, such as creatinine levels for patients on aminoglycosides.

Our Lady of the Lake Medical Center has set up its Discern Expert, part of Cerner’s PathNet LIS, to respond to a series of rules on when customers should be called back. "The technologist can just keep running results and doesn’t have to stop to look up a phone number or do a fax," says Donna Hoglen, LIS supervisor. Discern Expert will put results into a callback queue or fax them, depending on clients’ preferences. Results that need quick response, such as a glucose of 500, are flagged as urgent and put into a separate queue for immediate callback by a clerk.

"Many of our clients have their own rules," says Martha Delaney, director of new business development for ACM Medical Laboratory, which consists of a reference lab and three hospital-based facilities. Before going live on SCCSoft Computer Consultants’ expert system several years ago, ACM’s technicians and customer service representatives had to remember each client’s requirements. "We did it all manually," Delaney says. "Fortunately, our volume was much smaller."

Today, with more than 1,000 clients, ACM depends on its expert technology to send faxes at certain times and it depends on its online call list to alert staff to make phone calls. Oncology clients want test results immediately. Other clients get a summary list faxed at a specified time. Some clients get their results electronically. The system also accepts verbal orders from physicians and automatically faxes back the order for a signature. Client- or physician-specific rules take precedence over general ACM rules.

ACM also takes advantage of the multi-site routing capabilities in its expert system. The multi-site rules can be used to shift work from one site to another at peak testing times, to route work from a client to an alternate outside reference lab, and to change routing on holidays. "The testing site determined by the rules prints on the specimen label," says Delaney. "And rules change over time based on laboratory and client needs."


Expert systems are also used to autoverify results; those outside the norm are flagged for additional attention. The technology can be set to differing parameters. When an expert system first goes into use, parameters typically are defined narrowly so results are more likely to be scrutinized by a technologist. As acceptance of the new technology grows, the parameters can be broadened.

The Cleveland Clinic Foundation, which uses the Sunquest FlexiLab LIS, has configured autoverification parameters for hematology and chemistry tests. "This is a common feature of LISs today, but a lot of labs don’t make very extensive use of it," says Walter Henricks, MD, director of laboratory information services. Results typically are checked by a medical technologist, who validates them or sends outliers back for retesting. But in a modern laboratory, "you have thousands of tests and values being churned, and the technologist isn’t always able to figure out if abnormal values are inappropriate for a given patient," he says.

An expert system can sort through thousands of results much more consistently than a human, he says. That means technologists must scan only those results that fall outside parameters. For example, a potassium test that comes back as a 10 "would fail autoverification and show up on a list that’s checked by a person in the lab," he says.

At Alliance Lab Services in Cincinnati, "expected" results are automatically reported to the client, while results that don’t match delta failures are put on hold and displayed on screen for the technologist to check. Says Griffith: "We use a review list that displays everything that needs to be looked at. Results that have been autoverified as expected never get to the screen. All the tech has to deal with are things that are unexpected."

Using the LabWizard expert system from Pacific Knowledge Systems, Clinipath Laboratories, Perth, Australia, is autovalidating 70 to 95 percent of lab results in such areas as thyroid, lipid, sex hormones, chemistry, iron, hepatitis, serology, and prostate-specific antigen testing. "This [autovalidation] will become higher as we become more confident in the interpretation," says Wayne Smit, MD, chief executive of the diagnostic lab. LabWizard has been particularly valuable in alerting physicians to abnormalities on related test profiles, such as high urine white cell counts and elevated PSA levels or elevated low-density lipoprotein/cholesterol and hypothyroidism. Dr. Smit says Clinipath reviews one to 10 percent of autovalidated results as a quality measure.

St. Vincent Health System is autoverifying urinalyses with its Horizon Lab expert system and soon plans to add complete blood cell counts. Len Rea, chief technologist in hematology, says a CBC is more complex than a urinalysis. "With a CBC, you have to look at something like 18 pieces, any one of which can set off a flag," he says. "I don’t want to just look at normal values on a new admission and release the results. I also want to be able to autoverify that abnormal results haven’t shown significant change in a given time when a technologist has previously confirmed the results."

The expert system also helps St. Vincent adhere to government regulations in billing for tests, Rea adds. For example, a normal macroscopic urinalysis is reported to the physician and billed for as a macro. But if results are abnormal, the lab performs a microscopic urinalysis. Under government regulations, that must be billed for as a complete urinalysis as opposed to two tests. "The system handles that automatically and keeps us out of trouble," Rea says. On the other hand, he adds, the expert system can maximize potential revenue by recognizing each venipuncture and attaching a phlebotomy fee once per day.

Similarly, at Our Lady of the Lake Medical Center, the expert system can sort through hematology tests and bill at the appropriate level. Because of the complexity of the tests, "we were often billing at the lower CPT code to be on the safe side," Hoglen says. "That meant we were basically writing off more complex cases." Once a rule has been programmed into the system, "the computer monitors our testing and bills accurately for all the work that was done."

ACM Medical Laboratory has set up its expert system to track laboratory problems, including where they originate and how they are resolved. With hundreds of clients, technologists may not recognize a pattern occurring, "but the system does," says Delaney. "We can locate where we’re having an unusual number of problems," such as a physician’s office using the wrong specimen tubes. ACM then handles the problem diplomatically, perhaps offering to train staff within the office to handle specimens appropriately.

Reflexive testing

Expert systems commonly handle reflexive tests: determining whether a confirmatory test is needed based on a designated value or result. For example, at Our Lady of the Lake laboratory, some physicians want a free PSA test run if the PSA is greater than 2.5 ng/mL. Other physicians don’t want the free PSA. "Rather than doing it one way for everybody, we can set up the system to run the confirmatory based on what the physicians want," Hoglen says.

Free PSA is unusual because there’s not complete agreement on when it should be used. For most reflexive testing, the medical staff at Our Lady of the Lake agrees on when a confirmatory test is needed, and that rule is simply programmed into the system—such as running a Western blot if the initial HIV test is positive. The computer immediately decides a confirmatory test is needed and orders the test on the same specimen. That prevents the problem of forgetting to run a reflex test and having to ask the patient for an additional specimen. Another advantage: The expert system notifies infection control of positive results like HIV or hepatitis B.

"The [expert] rules have really allowed us to streamline our processes," Hoglen says. "The computer does it the same way every time, and you don’t see things changing from person to person or from shift to shift. It allows us to provide safer, more consistent, and more efficient care."

At the Cleveland Clinic, expert technology will automatically order a confirmatory test or will order serial dilution tests after a positive screening test. One example of a standard reflex order: In a cholesterol panel, if the triglyceride level is less than 400 mg/dL, the system will simply calculate the LDL value. But if the triglyceride level is greater than 400, the system orders a direct analytical quantitation of LDL because the calculation would not be valid for that level. "The logic to do the calculation or to order the direct LDL all occur within the LIS," Dr. Henricks says.

Alliance Laboratory Services has used expert logic for years to reflexively order manual differentials based on instrument results. "We started conservatively, doing more manual differentials, then gradually modified the criteria to the extent where it was clear a manual diff would not provide new information," Griffith says.

Duplicate tests

A system that can order confirmatory tests also can be programmed to eliminate what look like duplicate or unnecessary tests, but this is a step that many institutions are reluctant to take. Even though the government and other payers would like to see tests curtailed to save money, "you really are reluctant to override clinicians’ orders," says Rea. But "we do have the computer system eliminate obvious duplicate orders," he adds. To program his system to eliminate other types of unnecessary testing, which would streamline orders to better meet payer and government guidelines, would require lengthy meetings with clinicians to arrive at the rules, a step St. Vincent has not yet taken. "As an alternative," Rea says, "our HIShas a time frame window to alert the nursing staff of some of these possibilities."

Some institutions, however, are venturing into this area. At Our Lady of the Lake, the expert system will eliminate tests that are obvious duplicates, such as orders for a Chem 7 panel and a glucose. "The Chem 7 panel has a glucose in it," Hoglen says, "so the system will cancel the glucose."

In areas that are less clear, such as a CBC, the system will flag a questionable test but not cancel it. For example, with most patients, "a CBC once a day is adequate," Hoglen says. But for patients with a gastrointestinal bleed or those in surgery, "you may want to do one every 15 minutes. You have to leave the window open," she says. If the system detects a CBC that seems unnecessary, it alerts whoever placed the order with the question: "Duplicate order warning: Order anyway?"

ACM Medical Laboratory takes a similar approach: alerts rather than outright cancellation. "If you have a rule that says a manual differential should be done only once every three days, you set the system up to alert you if it’s done too soon," Delaney says. Anytime "we’re looking at restricting tests that a physician has ordered, we talk it over first with the physician," she adds.

Alliance Lab Services, which includes two large teaching hospitals, found that it had a problem with duplicate orders, Griffith says. That’s because, particularly at teaching hospitals, "a lot of different people are writing orders on the chart." So, working closely with nursing and medical staff, the laboratory identified tests that wouldn’t need to be done more than, say, once a week or once every hour.

If the system detects two or more tests of the same type ordered within the given time frame, "it will cancel the duplicate," Griffith says. A note is appended to the patient’s chart so that nurses and clinicians are aware of this step. "Initially there was some hesitancy to do this," she says, "but it’s turned out to be the biggest non-issue." The system also detects questionable tests, such as a PSA order for a female patient, and will display a warning on screen. "I look upon expert rules as Post-It notes," says Griffith.

Alliance Lab Services kept certain tests, such as blood gases, off-limits to computer cancellations. "If the specimen is drawn and brought to the lab, we will do the blood gases," Griffith says. "It isn’t worth arguing over."

Pushing the boundaries

Expert systems have capabilities that are not being fully exploited yet, not so much because of resistance to computerized medicine, but because of the time and resources that must be committed to change work processes. "There’s more we could do," acknowledges ACM’s Delaney, "but we have to give people time to adjust. You have to shepherd people through the changes."

Still, some laboratories are exploring the boundaries of what can be done, even to the point of allowing expert technology to interpret results. The Cleveland Clinic has its Sunquest system append comments related to test values. "These are mostly boilerplate messages," Dr. Henricks says, "and it’s up to the lab to define what they’ll be."

Our Lady of the Lake Medical Center allows its expert system to interpret complex findings, such as a hepatitis panel. "A hepatitis B workup has seven or eight different tests," Hoglen says. "The system will look at all the results and fire an interpretation." Hoglen worked closely with pathologists to program the system to make that determination. "When the system comes up with an interpretation, it can be modified by the pathologists," she adds, but as their confidence has grown, "they are basically giving free rein to the computer."

As soon as new computer code is available, Hoglen intends to deliver drug susceptibility alerts on bacterial cultures to clinicians immediately, so that a broad-spectrum antibiotic is not used any longer than necessary. Once laboratory results on a culture are available, "Discern Expert will notify the physician to switch to a narrow-spectrum antibiotic," she says. This lowers costs and lessens the likelihood of resistance. "The doctors have been begging for this," she says. "We’re pleased to have a computer system that will allow us to do this."

Working with Molis, Arnot Ogden is in the process of implementing an oversized terminal in the core lab. The terminal will continuously track and display the status of stat orders. "The techs will be able to tell at a glance which tests are approaching the promised turnaround time of one hour," says Dr. Wilson. "We think that this, along with autoverification, will significantly reduce the number of outliers in our turnaround time QA monitors."

Clinipath Labs in Australia uses its LabWizard system to add specialist pathologist opinions and recommendations to a range of pathology reports. These specialist opinions draw on present and historical results, tests in related areas, and clinical notes.

LabWizard is also being used to identify patients who are diabetic. "LabWizard can determine that test results mean that this patient is a diabetic," says Dr. Smit, "so it will send an instruction to the LIS to include diabetes on the list of conditions associated with that patient. Any future laboratory episode for that patient is then reformatted in the LIS to deliver results relevant to diabetic monitoring in a diabetic monitoring profile, complete with comments and further testing advice."

St. Vincent Health System has been one of the most aggressive in using expert systems, so much so that it has become a show site for McKesson, the distributor of its Horizon Lab system. "We have about 150 rules active now in our lab area," Rea says. "We have the system doing a wide variety of things, from simple calculations, reflex orders, tech comments on how to handle abnormal results, to results interpretations that are canned comments pathologists would have individually written a few years ago."

Later this year, using an upgraded version of the Horizon Lab software, lab and pharmacy will be more closely integrated. A prothrombin time or partial thromboplastin time test result will be forwarded to pharmacy to make a possible adjustment in the level of anticoagulant. "I will actually have a tie that lets me see pharmacy records and they can see mine," Rea says.

The future

The future will bring a closer linkage of LIS expert systems with other departments, especially pharmacy, nursing, and other clinical areas, and the electronic patient record. Says Dr. Henricks: "If you do electronic order entry, that’s the point where testing decisions are being made, and it’s not done with the LIS. But that’s where expert systems related to test ordering would be most relevant."

At this point, Dr. Henricks says, pathologists and other laboratorians must understand broader information technology issues if they want to have an impact beyond the laboratory. The HIS, which governs the entire hospital or health care system, "is the window through which tests and specimens come into the lab and results go out," he says. Consequently, pathologists should get involved in how HIS expert systems are programmed. "How are results displayed? How are tests named and grouped on the screen for ordering? With the explosion of knowledge in lab testing," says Dr. Henricks, "it’s hard for doctors to keep up with all the specialized aspects of testing. The knowledge has to go beyond the LIS."

Karen Southwick is a writer in San Francisco.