Whether point-of-care (POC) testing is seen as the ally of the clinical laboratory or its enemy depends less on the nature of today’s POC technologies than on the circumstances in which the laboratory operates. For the many laboratories struggling to get through the day’s work without being fully staffed in this time of shortage, POC testing can take off some of the pressure by shifting the performance of simpler tests to the inpatient bedside or outpatient clinic, even if the oversight responsibility for these tests still belongs to the laboratory.
Likewise, laboratories that serve busy emergency departments often welcome POC testing conducted there, since it frees their equipment and staff to handle stat-testing orders more smoothly and promptly. In facilities where the laboratory is treated as a cost center for accounting purposes, shifting some high-frequency tests to patient care areas can also reduce apparent costs, although this transfer of work hours to nonlaboratory staff is only truly profitable to the institution as a whole if the employees performing tests are paid less than laboratory personnel.
If the time of a registered nurse is being used instead of the time of a technologist to run the same test, for example, then there will be no benefit because nurses are typically paid more. Usually, though, the test is not the same as the one that would be run in the laboratory: POC tests are designed to be used easily by nonlaboratory staff and, in most instances, they require less time to perform. Even if expensive nursing hours are used, the savings in overall time may be worthwhile.
The size, layout, revenue sources, and working culture of the institution also play their parts in creating or dampening enthusiasm for POC testing. If a laboratory relies heavily on outreach work from medical offices to sustain it financially, then the expansion of POC testing in those referring offices is unlikely to be seen as positive. During this influenza season, for example, the shift to POC testing driven by the need to administer antiviral agents promptly may have dropped flu-testing volumes greatly for many (or most) laboratories.
For a laboratory where the bulk of work comes from inpatients enrolled in Medicare, however, with the prospective payment system covering all costs of the episode of illness with a single reimbursement, POC testing’s ability to reduce costs can be quite welcome.
The laboratory’s quality-assurance, training, and supervision responsibilities for POC testing also vary not only by law, but by institution. These may be beneficial extensions of the laboratory’s superior attention to quality in some hospitals, with patient care benefits to be expected. In other hospitals, the need to stay on the run to monitor testing in far-flung departments and satellite clinics may create more costs (and headaches) than it saves. Similarly, the laboratory’s authority over POC testing may be a relief in some facilities and an intrusion in others, depending on the internal political climate.
Despite many years of POC testing, such factors are still in flux in some institutions. If market trends are reliable indicators, however, then POC testing is heavily favored in most settings. POC testing has been spreading rapidly, and the revenues of POC-test suppliers have been climbing. Within the next 3 years, they are expected to increase even more rapidly, possibly reaching about $20 billion.
While some of this boom is attributable to cost and staffing factors favoring POC, much of the credit also goes to major advances in POC technology itself: reliability, ease of use, and low cost are accompanying an industry-wide push—both rapid and broad—into new applications that take POC testing where it could not previously go. Especially productive areas for recent development have been POC tests for patients suspected of having infectious diseases, diabetes mellitus, and cardiac disorders.
The improvement of testing technologies based on saliva samples is expected to lead to a number of new POC tests. Although, in many cases, their sensitivity and specificity may only equal (not exceed) that of tests that require blood or urine specimens, their widespread acceptance is likely to be driven by a strong patient preference for saliva sampling over other methods. In addition to saving patients the indignity of urine-specimen provision or the pain of blood sampling, saliva-based tests may save money for test providers by greatly reducing the staff time required to obtain a specimen.
A second trend is being seen in perinatal testing as a means of screening mothers about to give birth for both sexually transmitted diseases (STDs) and other disorders. As a public-health measure, this is sensible because entering active labor is sometimes the only thing that prompts a woman without access to perinatal care (or other health care) to seek medical care.
Some emergency and labor-and-delivery departments, especially those treating medically underserved populations, are using this opportunity to screen women in labor for diabetes or other suspected conditions. Even more often, STD testing is performed during labor, with growing adoption of HIV screening as a vital component of perinatal care for women whose HIV status is unknown. The US Centers for Disease Control and the American College of Obstetrics and Gynecology now recommend the use of POC tests for HIV as a means of decreasing HIV transmission from mother to infant during birth.1
In some settings, particularly large teaching hospitals, protocols have been introduced that are intended to streamline diagnosis of many disorders by combining POC testing with diagnostic imaging. An example is the combination of echocardiography with POC testing for B-type natriuretic peptide; this can hasten diagnosis of congestive heart failure.2 This trend has moved POC testing into the radiology suite (or into the hands of radiologic technologists and radiology nurses at the bedside) to a degree not seen before, so training challenges have sometimes arisen, but results so far appear promising.
POC testing for diabetes has moved into two new arenas: rural environments and critical care. POC capillary blood-glucose testing is being used in areas with high diabetes incidence and poor access to health care to diagnose diabetes.3 This greatly expands the reach of medicine into traditionally hard-hit rural areas of the United States such as Native American reservations, where access to a physician may be rare. By prescreening the local population for chronic and serious conditions such as diabetes, public-health services can make scarce resources count.
Bedside glucose monitoring through POC testing has also been expanded beyond patients known to be diabetic. Based on the premise that maintaining blood glucose within a narrow range can improve outcomes in the critically ill (including patients with surgical trauma), POC glucose testing followed by insulin therapy is being used to improve healing and decrease mortality.4
Another influence on the broader adoption of POC testing was the 2007 issuance of POC guidelines5 by the National Academy of Clinical Biochemistry. These evidence-based recommendations, grouped by diagnostic focus rather than by individual test, were based on literature reviews and outline how each type of testing can be applied to clinical practice; they also review areas in which POC testing cannot serve as a substitute for procedures performed in the laboratory. The areas covered by the guidelines are acute coronary syndrome, bilirubin, coagulation, critical care, diabetes, drugs and alcohol, infectious diseases, parathyroid hormone, occult blood, pH, renal function, and reproduction.
The guidelines were later supplemented with additional material on POC testing as affected by information technology (including standards and connectivity) and by methods for collecting specimens, conducting tests, and reporting results. The focus of this work,6 backed by the National Science Foundation and the National Institutes of Health, was the improvement of access to health care through broader POC testing in medical offices, emergency departments, and homes.
For this issue, major manufacturers of POC tests approved for use in the United States were asked to complete questionnaires concerning up to three of their products or product lines. Their responses follow in tabular form for easy comparison of features and benefits. The breadth of their offerings is remarkable, illustrating the degree to which this market has branched out from its simpler beginnings, when the ability to swab a bad-looking throat in the emergency department to detect streptococcal infection was a breakthrough.
Throughout the diagnostics industry, no serious conceptual, scientific, or financial brakes have been applied to research and development leading to new POC tests, so continued burgeoning of available choices can be expected to continue. As usual, when technical capability, creativity, and a ready market are combined, manufacturers will respond with a test for every niche. Since the POC market is far from saturated, the bubble of tests in development is likely to keep expanding, giving laboratories an ever-broadening range of POC choices for many years to come.
Kris Kyes is technical editor of CLP.
- Jamieson DJ, Cohen MH, Maupin R, et al. Rapid human immunodeficiency virus-1 testing on labor and delivery in 17 US hospitals: the MIRIAD experience. Am J Obstet Gynecol. 2007;197:S72-S82.
- Arques S, Roux E, Sbragia P, et al. Usefulness of bedside tissue Doppler echocardiography and B-type natriuretic peptide (BNP) in differentiating congestive heart failure from noncardiac cause of acute dyspnea in elderly patients with a normal left ventricular ejection fraction and permanent, nonvalvular atrial fibrillation: insights from a prospective, monocenter study. Echocardiography. 2007;24:499-507.
- Marley JV, Davis S, Coleman K, et al. Point of care testing of capillary glucose in the exclusion and diagnosis of diabetes in remote Australia. Med J Aust. 2007;186:500-503.
- Reed CC, Stewart RM, Sherman M, et al. Intensive insulin protocol improves glucose control and is associated with a reduction in intensive care unit mortality. J Am Coll Surg. 2007;204:1048-1054.
- Nichols JH, Christenson RH, Clarke W, et al. Executive summary. The National Academy of Clinical Biochemistry Laboratory Medicine Practice Guideline: evidence-based practice for point of care testing. Clin Chim Acta. 2007;379:14-28.
- Price CP, Kricka LJ. Improving healthcare accessibility through point of care technologies. Clin Chem. 2007;53:1665-1675.