When you have a pathology test it’s usually either because your GP or specialist doctor has requested it, or you are in hospital and tests are needed as part of your diagnosis, treatment or care.
Today, laboratory testing is performed in many different settings, from the large, highly automated central laboratory that performs thousands of tests a day to your own home, where you might do a pregnancy test or monitor your blood glucose levels.
Samples can be blood, urine, a throat or nose swab or a piece of tissue - even a biopsy taken while you are under anaesthetic on the operating table. Once collected, they must be delivered to the lab. Depending on the type of tests you are having your samples could go to any one or more of a number of different types of labs.
All laboratories are not the same for the simple reason that not all tests are the same. Just as tests vary in complexity, and the technology needed to perform them, so too laboratories vary in their complexity, the numbers and types of tests they can perform, the professionals who staff them and the technology they have available.
In Australia a large proportion of laboratory testing is done outside the public hospital system in private pathology laboratories. Most testing requested by family doctors, specialists in private practice and by doctors working in private hospitals, is referred to private pathology laboratories. In the state capitals and larger cities there are big private diagnostic laboratories that are actually not a single lab but a cluster of many specialist labs or departments. They employ hundreds of people – pathologists, scientists, technicians and many support staff. There are also smaller private diagnostic laboratories, especially in regional towns, which are generalists handling the common tests and sometimes a few special tests. These are often one or two person pathology practices with support staff.
Hospital labs run 24-hours, seven days a week and are geared to emergency work as well as the often life-threatening illnesses they see on a regular basis. Tests that are performed include those that are needed in emergency situations (such as markers for heart attacks and tests needed for checking the suitability of blood for transfusion) and those done in large numbers which require automated testing analysers. Hospital laboratories are generally used by inpatients and outpatients for the particular hospital. However, as a patient you may never visit the laboratory unless your doctor asks you to go there to have a sample taken.
Hospital laboratories are usually organised into sections depending on the type of testing to be performed. For example, there are usually sections for microbiology (the study of bacteria and viruses), haematology (the study of blood cells), clinical biochemistry (the study of the chemical composition of the blood), blood transfusion and anatomical pathology (testing of tissue samples).
Smaller laboratories are attached to regional hospitals, spread thoughout most states in Australia.
Laboratory tests may also be performed at the actual point of care - in other words, where the patient is (at the bedside or in the GP surgery or clinic) rather than in a distant laboratory. Laboratory tests in these places are usually limited to uncomplicated tests. Tests done at the point of care tend to be time-consuming for the personnel involved and relatively expensive compared to laboratory tests, but they are more convenient for patients and provide rapid results.
Point of care testing is increasing as technological advances bring about portable devices that are easy to use and produce immediate results. Examples include blood glucose tests, blood gas monitoring systems and analysers for tests for blood clotting and to detect heart attacks.
Tests performed at the point of care must comply with standards just like those performed in central laboratories (see Laboratory Accreditation article), and proper systems of quality control should be operated. It is expected that point of care testing will continue to develop as new devices become available, in part because they may reduce delays and provide immediate information to doctors, allowing more timely medical treatment.
Some tests are being adapted for use at home as patients take on responsibility for their health care. Common home tests include pregnancy tests and ovulation predictors for women, blood glucose monitors for diabetics and prothrombin-time tests to monitor the doses of drugs that prevent clotting of the blood.
Home tests are usually bought over the counter at pharmacies. Some may require a doctor’s prescription in order to obtain reimbursement. The advantages of home tests include convenience and rapid results.
However, while the devices appear simple it is possible to obtain the wrong results if the instructions that accompany the device or test are not carefully followed. Such instructions include information on the correct storage of strips or other reagents and using the right type of sample whether blood or urine.
It may also be necessary to seek professional advice to understand the significance of a particular result and you should obtain this from your doctor or pharmacist.
Other home tests are available over the internet but users should be cautious about their use since at the moment there is no way to be sure that these devices conform to specific quality requirements. Again, you should discuss the suitability of these tests with your doctor.
Tests that are less-commonly performed or that require special equipment or expertise may be referred to a specialist laboratory elsewhere. They are staffed by pathologists and scientists with high-levels of expertise in performing complicated and unusual tests – esoteric tests. Many of these tests require sophisticated and expensive technology.