Point-of-care testing


Point-of-care testing is defined as medical diagnostic testing at or near the point of care—that is, at the time and place of patient care. This contrasts with the historical pattern in which testing was wholly or mostly confined to the medical laboratory, which entailed sending off specimens away from the point of care and then waiting hours or days to learn the results, during which time care must continue without the desired information.

Technology

Point-of-care tests are simple medical tests that can be performed at the bedside. In many cases, the simplicity was not achievable until technology developed not only to make a test possible at all but then also to mask its complexity. For example, various kinds of urine test strips have been available for decades, but portable ultrasonography did not reach the stage of being advanced, affordable, and widespread until the 2000s and 2010s. Today, portable ultrasonography is often viewed as a "simple" test, but there was nothing simple about it until the more complex technology was available. Similarly, pulse oximetry can test arterial oxygen saturation in a quick, simple, noninvasive, affordable way today, but in earlier eras this required an intra-arterial needle puncture and a laboratory test; and rapid diagnostic tests such as malaria antigen detection tests rely on a state of the art in immunology that did not exist until recent decades. Thus, over decades, testing continues to move toward the point of care more than it formerly had been. A recent survey in five countries indicates that general practitioners / family doctors would like to use more POCTs.
The driving notion behind POCT is to bring the test conveniently and immediately to the patient. This increases the likelihood that the patient, physician, and care team will receive the results quicker, which allows for better immediate clinical management decisions to be made. POCT includes: blood glucose testing, blood gas and electrolytes analysis, rapid coagulation testing, rapid cardiac markers diagnostics, drugs of abuse screening, urine strips testing, pregnancy testing, fecal occult blood analysis, food pathogens screening, hemoglobin diagnostics, infectious disease testing and cholesterol screening.
POCT is often accomplished through the use of transportable, portable, and handheld instruments and test kits. Small bench analyzers or fixed equipment can also be used when a handheld device is not available—the goal is to collect the specimen and obtain the results in a very short period of time at or near the location of the patient so that the treatment plan can be adjusted as necessary before the patient leaves. Cheaper, faster, and smarter POCT devices have increased the use of POCT approaches by making it cost-effective for many diseases, such as diabetes, carpal tunnel syndrome and acute coronary syndrome. Additionally, it is very desirable to measure various analytes simultaneously in the same specimen, allowing a rapid, low-cost, and reliable quantification. Therefore, multiplexed point-of-care testing has become more important for medical diagnostics in the last decade.
Many point-of-care test systems are realized as easy-to-use membrane-based test strips, often enclosed by a plastic test cassette. This concept often is realized in test systems for detecting pathogens. Very recently such test systems for rheumatology diagnostics have been developed, too. These tests require only a single drop of whole blood, urine or saliva, and they can be performed and interpreted by any general physician within minutes. Recently, a portable medical diagnostic device called “BioPoC” has been reported which employs free-standing enzyme-modified responsive polymer membrane-based biosensors and a newly devised low-cost transduction principle for the detection of H. Pylori and urea.
Recently, it was proposed that the utilization of smartphone‑based microfluidic systems can provided a POCT technology for rapid detection of COVID-19 using saliva specimen. Since the integration of both smartphones and microfluidic systems has provided a technology that is user-friendly, easily accessible, miniaturized, and portable, using smartphone-based microfluidic PCR or RT-LAMP alongside ELISA has the potential to allow the rapid detection of COVID-19 in patient samples, particularly saliva. The combination of smartphones or tablets with microfluidics will allow continuous and easy health monitoring of individuals or populations during and after COVID-19 outbreaks. Fabricating and developing such fast and accurate devices can effectively equip us to handle current and probably future outbreaks.

Benefits

The coupling of POCT devices and electronic medical records enable test results to be shared instantly with care providers. The use of mobile devices in the health care setting also enable the health care provider to quickly access patient test results sent from a POCT device. A reduction in morbidity and mortality has been associated with such rapid turn around times from a study using the i-STAT to analyze blood lactate levels after congenital heart surgery.
POCT has become established worldwide and finds vital roles in public health. Many monographs in the Thai and Indonesian languages emphasize POCT as the normal standard of care in disaster situation.
Potential operational benefits include more rapid decision making and triage, reduced operating times, high-dependency, postoperative care time, emergency room time, number of outpatient clinic visits, number of hospital beds required, ensuring optimal use of professional time and reduced of antimicrobial medication.

Funding

In the United Kingdom the GP contract leaves the cost of point-of-care testing, which may be substantial, with the individual GP practice, which the cost of medication is met by the
clinical commissioning group, which, as the House of Commons Health and Social Care Committee noted in October 2018, creates perverse incentives.