Moving the laboratory to the patient
Healthcare providers (and patients themselves) want to know as soon as possible the condition of the patient - whether healthy or sick, in or out of control, trending up or down. To date, central laboratories have provided this diagnostic information and do so by means of batch processing systems using large, complex, technology-specific testing devices. However, advances in microelectronics, microfluidics and microfabrication are enabling diagnostics manufacturers to break this tradition and create a new generation of small, portable devices that provide near-instant results wherever the patient is located.
Point of Care Testing (PoCT) may be the way of the future by providing near-instant test results. This will be of immense benefit to both medical practioners and, more importantly, patients, allowing informed health decisions to be taken far more quickly than under present systems.
Traditionally, testing has been conducted through central laboratories in a hospital setting or at a commercial reference laboratory. In most cases, central laboratories require 4-24 hours to provide results for routine tests, while reference laboratories can require up to 48 hours. Frustration over the inherent costs and inefficiencies associated with such a slow turnaround for testing is driving the health carers towards PoCT.
However, the requirements for PoCT systems will need to be highly stringent. The systems will have to offer a broad menu of the most commonly ordered blood tests in the areas of chemistry, coagulation, immunochemistry, and haematology. It is expected that a menu of 70 routine tests representing these four areas will be able to cover more than 90% of the testing needs of alternate-care sites and 60% of the needs of hospitals.
The accuracy and precision of PoCT instruments will have to be equivalent to those that can be achieved by large testing devices used by central laboratories and data should be in a form that will make review and identification of unacceptable results simple for the operator to recognise. The results will need to be saved in a form acceptable to the doctor, laboratory director and licensing agency or accrediting body.
The PoCT device must be simple to operate and easy to learn as the users will include untrained personnel. The users will have to be protected from exposure to biohazardous materials.
According to the Pathology Section of the Australian Government Department of Health and Ageing, potential advantages of PoCT include:
- Enhanced clinical management;
- Greater patient compliance with pathology requests;
- Greater convenience and satisfaction for patients - speed of diagnosis and treatment decision with fewer visits to the doctor;
- Better health outcomes for the patient;
- Greater satisfaction for the GP;
- Savings in cost and time for patients because PoCT is done at the time of consultation; and
- Improvement in doctor/patient relationship.
Possible disadvantages include:
- Inappropriate testing leading to increased costs with no benefits to the patient or to society;
- Inaccurate results which lead to less than optimal health outcomes for the patient with additional testing and treatment; and
- Possible increased consultation and waiting time.
For PoCT to be widely accepted and used, the cost per reportable result will have to be the lowest option available to the healthcare provider and payer.
In Australia, the Pathology Services Table lists the pathology tests for which Medicare benefits are payable. Only a few tests, defined as simple and basic, can currently be performed in a non-laboratory environment and be rebated under the Medicare Benefits Schedule.
A report to the Medical Services Advisory Committee in 2001 indicated that there is a lack of evidence around the clinical and economic benefits of PoCT. The report recommended that further information be collected on the diagnostic performance of PoCT in the community setting.
The Department of Health and Ageing is currently planning to conduct a PoCT trial in general practices in a range of Australian locations to investigate and evaluate the safety, clinical effectiveness and cost effectiveness of point of care testing in general practice.
Secondary research questions will be evaluated during the trial. These will include:
- Is it safe to perform PoCT?
- Is the effectiveness of PoCT at least as good as for the same tests using pathology laboratory testing?
- Is it the same or more cost-effective to perform PoCT compared with pathology laboratory testing?
- Are patients and other stakeholders more satisfied with PoCT than with pathology laboratory testing?
- Are there differences between urban, rural and remote geographic regions in any of the parameters measured?
- Would the regulatory environment used for the trial meet the needs of all the stakeholders if PoCT were to be made generally available?
- What would the appropriate MBS fees be for the PoCT tests selected to be in the trial?
The tests will include: anticoagulant therapy (INR); hyperlipidaemia (total cholesterol, high density lipoprotein and triglycerides); and diabetes (glycated haemoglobin and microalbumin).
The Australian Institute of Medical Scientists (AIMS) considers it essential that medical scientists be involved in introducing new technology for PoCT and in calibrating and maintaining equipment. It would also want to be involved in training users of the devices and reviewing the quality control and the cost effectiveness in communities and hospitals.
The progressive development and improvement of point of care instruments has expanded the role of PoCT equipment for community-based management of patients, especially diabetics and those on anticoagulants. To ensure consistent testing accuracy, validation of equipment performance should be carried out regularly at an accredited pathology laboratory. In addition, medical laboratory scientists should be involved in training personnel using these devices.
AIMS also recommends that legislation includes mechanisms for ongoing validation of point of care testing equipment and test outcomes.
The development of affordable diagnostic technologies as handheld devices is continuing at an increasing pace. The Canadian government is funding the development of PoCT devices that will provide accurate test results for emerging and re-emerging infectious diseases. Test results within 15 minutes for West Nile virus is the first project for the proposed 'finger prick' technology.
As the change from laboratory to point of care testing appears inevitable, it will be up to a coalition of scientists, medical practioners and government to ensure that patients receive equivalent or superior outcomes affordably. Medical scientists will move away from providing test results in the laboratory and into the training of unskilled operators, the accreditation and validation of equipment and procedures and research into new test procedures that can be performed at the point of care.
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