Point-of-care testing – advantages and limitations

Dr David Howdijam (MD) *

In the early days of medicine, few medical tests existed that were done at the patient’s bedside. By the 1980s, with the advent of automated technologies, clinical laboratories could run large numbers of tests at low cost. It became common to send samples away to laboratories and then wait days to weeks for results.

As the need for faster test results has grown and certain testing devices have become portable and easy to use, medical testing and the technologies have evolved dramatically again. Results from clinical laboratories remain a crucial component of healthcare, and they are now complemented by tests performed outside of the laboratory, wherever the patient is.

Point-of-care (POC) testing spans so many areas of medicine that it is best defined by where it’s done – anywhere outside the centralised laboratory – rather than by the kinds of tests that are performed. It may be referred to by many different names, such as near-patient testing, remote testing, satellite testing, and rapid diagnostics. In general, point-of-care testing encompasses any tests that are performed at or near a patient and at the site where care or treatment is provided. Results are typically available relatively quickly so that they can be acted upon without delay.

POC testing can happen in a wide variety of locations: at home, at a healthcare practitioner’s office, in the emergency department, in an infectious disease containment unit, in ambulances, at an accident scene, in the military, in the radiology department, on cruise ship, or even on a space shuttle. And a wide variety of persons can perform POC tests, including laboratory professionals, emergency first responders, radiologists, doctors, nurses, physician assistants, or other healthcare practitioners. They may even be done by the patients themselves, sometimes called “self-tests” or “home tests”.

Devices for POC testing come in an array of forms. They may use basic dipsticks as with urinalysis, hand-held devices like glucose meter (or glucometer), or sophisticated molecular analysers to detect infectious diseases. A healthcare practitioner may use a hand-held device to perform a test at a patient’s bedside. Alternatively, the healthcare personnel may collect a blood sample from the patient and send the sample to a main/satellite lab, where the sample is processed and tested on sophisticated instruments.

POINT-OF-CARE TESTING IS GROWING

As healthcare becomes more consumer-focused, the need for convenient diagnosis, monitoring, and screening tests is growing worldwide. In some cases, technology has caught up; testing devices that are smaller, more portable, and easier to operate have been developed. The main reason for growth of POC testing is faster results that help the patients and doctors make faster, and hopefully better decisions.

With results in hand during the first consultation itself, one can receive immediate follow-up testing or treatments without returning for another visit. POC testing is useful as medical care shifts to a focus on prevention, early detection, and managing chronic conditions. There is also a growing need for rapid screening for infectious diseases like HIV, dengue fever, malaria, and influenza.

Infectious disease tests are useful in community clinics and remote or resource-limited areas where there may not be easy access to a central lab or where there is limited infrastructure for transporting samples. When time is of essence, such as in an emergency departments or at accident scenes, POC tests provide immediate information about blood gases, electrolytes, or troponin.

BENEFITS OF POC TESTING

When used properly, POC testing can lead to more efficient, effective medical treatments and improved quality of medical care.

At home, POC tests allow for more frequent and more consistent testing and can empower the patient to take control of one’s medical care. Ideally, the end result is higher quality care.

POC testing is also crucial in emergency situations and in operating room. They are also useful in disaster situations or any scenario that prevents access to power, water, and laboratory infrastructure.

When used in a healthcare practitioner’s office, POC testing can reduce follow-up visits or calls. POC testing can also provide test results in locations where clinical laboratories don’t exist or are too far away.

CAUTIONS

While many POC tests are designed to be relatively simple and have low risk, they are not error-proof. Individuals using POC tests, even healthcare practitioners, must carefully follow test directions and be familiar with the test system. If not performed properly, POC tests have the potential to lead to serious health consequences. It is important that the convenience of POC testing does not tempt the user to apply them beyond their intended purpose or misinterpret results.

Care must also be taken to compare results from different sources. Just as test results may not be consistent from laboratory to laboratory, they may vary between POC testing techniques, or between laboratory results and POC test results. While speed is often one of the advantages of POC testing, the results may not be as specific or sensitive as centralised laboratory test results.

POC tests may also deliver a more limited range of results compared to a full laboratory work up. So following up with laboratory test will likely be necessary after an initial test at the point of care. One benefits most from POC testing when results from a laboratory are also coordinated and when POC test results are not used in isolation.