When your GP requests you have a blood or other type of pathology test it will almost certainly be transported to and analysed in a central laboratory using equipment that can analyse many different tests on the same specimen. The same will apply when you have tests done as part of a hospital visit or inpatient stay. The details of this type of central laboratory testing are described elsewhere (Inside the Lab).
But developments in technology have made it possible to analyse samples using much smaller equipment and these devices can be used by the patient or by healthcare professionals seeking to produce a result almost immediately as part of the consultation. This type of testing is often referred to as Point-of-Care-Testing (POCT) or occasionally as Near Patient Testing or Bedside Testing. POCT can occur at various locations including the home.
Last review date: December 17, 2015
History of laboratory testing and technological development
The development of pathology or laboratory testing is interesting in that over several centuries it has come full circle. The first testing of body fluids took place at the bedside, at the home or in a hospital ward, places now collectively called the point-of-care. As the science evolved, testing moved away from the bedside and laboratories were established. Technology developments in the latter half of the last century contributed to major advances in instrumentation resulting in the laboratories of today, located in major centres and cities of Australia, which are measuring many different analytes using technologically complex instruments.
More recently, technological developments such as the miniaturisation that we see in many consumer devices including mobile phones, is also being reflected in smaller blood and urine analysis instruments. The commonest example of these is the blood glucose meter described later but the increasing ability to now measure many different tests using relatively small devices is enabling testing to move back to the patient and contributing to what has been called more patient-centred care.
A key distinguishing feature of many point-of-care tests and devices is that they use whole blood rather than or which is used in the laboratory. To obtain the latter from a whole blood sample requires it to be spun or at high speed to separate the cells from the clear liquid - serum or plasma. Centrifugation is not an easy process to perform outside of a laboratory hence the need to develop technology that can analyse whole blood. Furthermore, it is relatively easy to obtain the latter through a small finger prick rather than using a needle and syringe which is what happens when you have blood collected for tests to be done in the laboratory.
The commonest example of home testing is the pregnancy test, purchased usually at the pharmacy but used in the home. Another relatively common example is home glucose monitoring sometimes referred to as self-monitoring of blood glucose or SMBG (see also Home Tests page).
If you are diabetic and taking insulin you will more than likely be measuring your glucose up to 4 times a day by taking a finger prick sample, placing a small drop of your blood on a strip which is inserted into a small glucose meter and which produces a glucose result after 15-30 seconds. Enormous technology advances have in the space of 40 years reduced the size of these devices so that most are hand-held and they are much easier to use. However, they are not fool-proof, and so require skills and care with use if they are to produce the correct results, an issue which we will return to later in this article.
Some pharmacies will conduct POCT for a variety of tests. Again, the most common of these is glucose since meters and glucose strips can be purchased in the pharmacy and some will play an active role in helping patients manage their diabetes. As part of this management they may also measure lipids such as cholesterol
. Such tests may also be conducted on non-diabetic patients as part of healthcare screening programs.
Point-of-care testing in hospitals and other healthcare facilities
The central laboratory model works extremely well for patients living in the cities or localities reasonably close to major centres. For patients and consumers living in rural and remote locations, access to pathology services can be more difficult. Thus, if you go to see your GP in the country or spend some time in a country hospital, there may be some delay in receiving results as pathology tests are likely to be sent away to a laboratory, which may be many hundreds of kilometres away.
With the advances in technology described earlier, it is now possible for commonly requested tests or those tests where results are needed quickly, so-called critical analytes, to be performed on relatively small devices within the country hospital or GP practice. These devices are usually operated by nursing or other healthcare staff but the supervision of the testing and its overall management is often by laboratory staff who may do this remotely from their central laboratory or by periodic visits to the facility doing the testing. Thus most states in Australia now have so-called point of care testing networks which provide a limited menu of tests in small country hospitals and other healthcare facilities and these are generally managed by public hospital or pathology providers.
Testing by GPs and physicians
As indicated earlier, GPs send most if not all their testing to the central laboratory. Exceptions to this are a growing number of GPs now conducting a coagulation test called INR in their practice on those patients who are taking warfarin as an anti-coagulant and who need to be monitored to ensure that they have the optimal amount of warfarin in their bloodstream. While central laboratories do organise special warfarin testing clinics to improve the convenience for the patient, in some cases testing by the GP at the time of the visit is more convenient and therefore popular with patients.
Some specialist physicians such as those who look after diabetics may also conduct testing within their practice such as tests for lipids and glycated haemoglobin, all of which can now be performed on relatively small devices. They offer this service for the convenience of their patients and also because they believe that having the results immediately available improves the value of the consultation.
In countries such as the US, Scandinavia and Switzerland, GPs or family physicians perform a much wider variety of testing including tests for infectious disease such as influenza and HIV. However, in Australia, primarily because POCT is not generally reimbursed on the Medical Benefits Schedule, GPs only perform limited testing within their practice such as for INR, where they bear the costs of testing themselves.
Future developments in POCT
It is likely that the volume of POCT will increase, not so much in the home, but more likely in healthcare facilities such as GP surgeries, small country hospitals and possibly pharmacies, but it will still be far less than the volume of testing done within the conventional laboratory. There are two reasons for the probable increase; one is advances in technology offering smaller and higher quality devices. Second, is the availability of evidence that shows the benefits of POCT. One example of the latter is the use of POCT in regional South Australia where as part of a cardiac care program it has reduced the mortality and morbidity associated with heart attacks of patients living in the country to the same level as that of patients residing in Adelaide.
However, a note of caution is required. While there have been major advances in technology there are challenges in reducing the size of a testing device and achieving the required quality of the test. By quality we mean the ability of the device to consistently provide the correct answer. An example is glucose meters, which have become both smaller and easier to use over the years. The quality of these devices has also improved but it is not yet at the same quality level as a glucose result measured in the central laboratory. For a diabetic monitoring their blood glucose at home, assuming the meter is used correctly, the quality is quite sufficient to guide their therapy. But for other tests, not all POCT devices are of sufficient quality that they can be used safely for clinical purposes. That will change as technological improvements become available but it is important to be aware that devices can be sold or made available to consumers in Australia which may not be of sufficient quality to provide safe and accurate results.
If you are thinking of purchasing a point-of-care testing device, consult with your doctor and seek their advice. Alternative organisations that can provide specific advice and support for POCT are the Australian Point of Care Practitioners Network and Diabetes Australia.