What are the disadvantages of point of care testing?

Índice Show

POCT testing
Benefits within a healthcare setting
Benefits outside a healthcare setting
Comparison to core laboratory testing
Integration planning

View PDF

Volume 4, 1 April 2016, Pages 22-29

https://doi.org/10.1016/j.plabm.2015.12.002Get rights and content

Electronic Medical Record

Positive patient identification

POCT

EORLA

Eastern Ontario Regional Laboratories Association

CSCC

Canadian Society of Clinical Chemists

ADT

Admission, Discharge and Transfer

EMR

electronic medical record

Physicians no longer have to wait hours to get laboratory results. The growing use of point-of-care-testing devices now makes it possible for doctors to see in near real time vital information about their patients. But some doctors who have adopted the technology say a number of drawbacks still exist with these devices, and the growing use of them raises questions about patient safety.

Judy Mangion, M.D., a cardiologist at Brigham and Women's Hospital in Boston, uses GE Healthcare's portable ultrasound system, Vscan. She said the device, about the size of a cell phone, has had an impact on the way she and her colleagues deliver care. The device makes it possible to get a glimpse of what is happening in a patient's cardiovascular system more quickly than traditional ultrasound machines, which are less portable.

"These devices do allow you to get ultrasound imaging to people and places that might not easily have access," Mangion said. "It does improve access substantially."

However, the device is not without its detractors. Battery life is limited, images generated from the Vscan device cannot be uploaded to the hospital's picture archiving and communication system, and images are less detailed than full echocardiograms, Mangion said. Additionally, there are no standards for appropriate use, which she worries could lead to unnecessary full echocardiograms.

"What this device potentially does is open a can of worms in that, because it's relatively inexpensive and so portable, [clinicians] can start to think about using this as a screening tool," Mangion said. "That may lead to more comprehensive [tests] being requested."

These kinds of concerns are common in other point-of-care testing devices. While new technologies offer physicians a way to quickly assess patients' condition, the fact that the tools were developed recently means there is little to no consensus on how to use them most effectively. Yet, even with drawbacks, doctors are still eager to make use of point-of-care testing devices.

Dov Frankel, M.D., assistant medical director of the emergency department at Sinai Hospital of Baltimore, said he petitioned his hospital's executives to purchase Abbott Laboratories' i-STAT point-of-care testing system because of the rapid blood test results it delivers.

He most frequently uses the device to perform Chem-8 panels, which measure patients' blood for sodium, potassium, chloride, bicarbonate, blood urea nitrogen, creatinine, glucose and calcium. The device gives Frankel access to measures of these compounds, which he said provide critical information about a patient's condition in less than two minutes. Before point-of-care testing was available, sending samples to the lab and waiting for results could take more than an hour, he said.

Speed is particularly important among stroke patient cases. Frankel said that doctors need to know a patient's prothrombin time, which is a value measuring blood coagulation, before administering medications to stroke victims.

Physicians need to know the strengths and weaknesses of point-of-care testing devices.

"Time is of the essence there, and you don't have an hour to wait for that value," Frankel said. "There's no way someone is going to push that medication if you don't have that value."

Still, he added that the point-of-care testing device is no replacement for laboratory testing because the range of values the device can test for is more limited than full lab workups. There is as tradeoff between speed and inclusiveness.

John Petersen, director of Victory Lakes Clinical Laboratories and point-of-care testing, associate director of clinical chemistry, and professor of pathology at the University of Texas Medical Branch, takes a similar view of point-of-care testing. While rapid results represent an advantage, devices do not always deliver the best quality results.

For example, he said that point-of-care glucose meters can be less accurate than full lab blood sugar tests. This can make a difference for diabetes patients who are on tight glucose control plans. Any variation in test results could throw off a patient's medication regimen.

"I don't think glucose meters are accurate enough to do [tight glucose control]," Petersen said. "They get you in the ballpark, but if you need a really precise number, at this point they can't do it."

Ultimately, Petersen said physicians need to know the strengths and weaknesses of point-of-care testing devices. Just because they do not offer the most accurate test results does not mean they shouldn't be used. The portability and rapid results they offer can help steer a physician in the right direction, giving them an idea of a patient's condition and allowing them to start the patient on a treatment plan. This can buy the doctor time until a more complete workup is completed.

Mangion agreed. She said that properly training users on all the functions of a point-of-care testing device is the key to making sure it is used correctly and delivers the greatest benefit possible. Without proper training, clinicians may expect more out of the device than it can effectively deliver.

Let us know what you think about the story; email Ed Burns, News Writer or contact @EdBurnsTT on Twitter.

Point-of-care testing (POCT) is used to refer to any patient testing that is done at, or near, the actual location of the patient. But how does software enable these testing capabilities, and are the results comparably applicable to the results in the lab?

POCT testing

The Clinical and Laboratory Standards Institute (CLSI) in the United States has published standards to address some of the concerns with operational and technical issues that can occur with POCT. This article will not focus on that, or the regulatory perspective of the testing. It will focus more on the healthcare facility, physician and patient experience, and POCT outcomes. The major objectives for healthcare apply to any experience a patient has with their healthcare—whether it is in a hospital, clinic, physician office, at home, or in a laboratory. The objectives are focused on quality, accuracy, speed, cost, and outcome. Fortunately, the facility and physician also focus on these areas for defining success. It should also be noted that the tests performed at the point-of-care are typical clinical analysis tests such as:

Bilirubin
Cardiac markers
Coagulation
Critical care
Diabetes
Drug testing
Infectious disease
Occult blood
Parathyroid testing
pH
Renal
Reproduction

Benefits within a healthcare setting

The largest benefit of POCT is that it can be done rapidly and be performed by clinical personnel who are not trained in clinical laboratory sciences. Rapid test results can provide a physician—and other clinical personnel—with answers that can quickly help determine a course of action or treatment for a patient. This has obvious benefits in almost any setting—from the emergency room to a patient receiving in-home care. Having faster access to test results when being presented with a patient for the first time—during a flare up of a known issue or when a new symptom appears in a patient currently under treatment—provides a physician with answers when they are with the patient, or going to be seeing a patient, in a matter of minutes.

The health cost benefits of using POCT have been shown to be beneficial to the facilities that utilize it. The speed in which a clinician receives an answer, provides a diagnosis, and executes a treatment plan is increased significantly with POCT. This also helps to reduce a patient’s length of stay in a healthcare facility, enabling the physician and other clinical staff to provide care to other patients while reducing the cost of healthcare for each patient. It has also been shown that readmittance is significantly reduced by wearable monitoring and testing devices when patients are discharged with them.

The technology used to test at the point-of-care has advanced providing easy to use, handheld devices that are able to be integrated with other healthcare applications within a facility. This provides a better quality assurance (QA) environment for data exchange and ensures that patient data is up-to-date and readily available to any healthcare provider treating that patient. The software embedded in these devices has also progressed to provide analysis-based results without the necessity of training the clinical staff on the details of the interpretive science.

Benefits outside a healthcare setting

Mobile testing and monitoring devices have emerged to provide advanced care, mobile monitoring, and self-administration of drugs to patients—providing them a better quality of life. These devices range from home health monitoring of vital statistics, to periodic testing. Patients and home healthcare staff are able to perform remote tests and automatically transmit those results back to the care facility. Healthcare employees including nurses, case workers, and physicians are able to view those results over a period of time as well as in real time to determine if changes in treatment plans are necessary or to evaluate the efficacy of a current plan. In urgent cases, these devices can call an ambulance.

Devices that patients can wear are able to monitor, record, report, and administer drugs such as continuous glucose monitoring (CGM) devices and insulin pumps, which provide for better control over blood sugar levels, automatic administration of insulin, and even provide alerts if blood sugar is too low or too high. These pumps also store historical readings so that a physician following the patient can see their ranges over time and help determine patterns or areas for correction of spikes or dips. Apple has just launched their Apple Watch Series 4 with a built in EKG (Apple calls it ECG) and fall detector, and there are now portable EKG and ECG detectors that connect to Blutooth that are commercially available for $100.00. These devices provide a better life quality for the patient while
ensuring a consistent and safe level of care.

Comparison to core laboratory testing

Testing can happen rapidly and be done by clinical personnel who are not trained in clinical laboratory sciences. This can also be an obvious detriment to the testing process. POCT can involve a variety of tests. Many handheld, wearable or bedside devices are specific to a particular test. Most of the personnel conducting POCT are not laboratory-trained personnel. A lack of training in laboratory testing implies a lack of understanding of the science of laboratory assays and practices for determining the reliability of test results. There is also a lack of knowledge of the particular test method which in a core laboratory includes both pre-analytical and post-analytical processes. These processes are key to determining the quality and accuracy of a test result in given situations.

Lab instruments provide robust analytics during the testing process to include the QA program and addresses pre- and post-analytical concerns. Testing done in a core laboratory with integrated instrumentation automatically provides key information. Examples include QA on reagents, lot numbers, expiration dates, testing accuracy, Westgard rules, and test results directly incorporated into the laboratory information system (LIS) which are stored directly within the patient case. Manual POCT does not provide all the necessary information including material handling data, result reporting and comments, and in some cases (depending upon the device) test results have to be manually entered into the facility’s database—which is not only time consuming but is also increases the risk of human error.

Integration planning

Historically, the technology that powers POCT has largely been focused on the hardware aspect of testing and the embedded software—or middleware—was mainly concerned with the specific device and either a single test or a range of tests that fall under a focused category, e.g.: diabetes. Whereas technology in the lab is robust and can be fully integrated within an IT infrastructure that supports the full range of hardware (instrumentation), software applications (LIS, remote ordering, reporting solutions, QA and QC, inventory), as well as integration to electronic health records, health information systems, etc.

However, the embedded software and middleware associated with POCT devices has continued to advance significantly. Facilities looking to incorporate POCT should conduct a use case evaluation—understand where the biggest benefits are. Most evidence-based studies show those areas to be around emergent care or a chronic monitoring and management situation such as home care, emergency room, ambulance, and bedside. Medical directors and laboratorians are now routinely charged with overseeing POCT as part of the laboratory operations and provide training to the staff using these testing devices. There should also be a plan for integration of the devices into the overall IT infrastructure of the facility. The software in some of these devices has evolved significantly in the past several years to be very robust and mirror what a “mini lab” would be capable of. The key is in choosing the right device and making sure that the software capabilities are maximized as a part of the overall IT strategy.

Mitch Fry, a healthcare industry executive, led a charge to have the manufacturers of these devices standardize their output for better integration into the overall healthcare workflow. Dr. Tom Tiffany, retired CEO, PAML, and consultant says, “When used appropriately to see if an action is needed or if an issue or illness can be put to rest, point-of-care testing is extremely advantageous.”

A company in Spokane, WA, GenPrime, a provider of portable lateral flow readers and microbial analysis systems used by healthcare providers, homeland security, and fermentation science industries has increased the former 50 percent accuracy of reading an output by eye to 95 percent accuracy using an FDA approved algorithm and their devices store the reading for defensibility.

Conclusion

There are clear pros and cons to POCT versus laboratory testing. There are situations where POCT can provide a definite advantage to the treating clinician, have minimal risk, better cost savings, and provide a quality healthcare experience for the patient. However, core laboratory testing is more advanced, follows the process and science for laboratory testing, and is fully integrated with the technology necessary to ensure results are accurate, analyzed, validated, and recorded. There are clearly situations where each method excels. Nonetheless, the gaps are quickly being closed and the two methodologies are merging through software technology.