Introduction
For many people, clinical laboratory testing is an invisible side of medical care. Yet many of the decisions your health care provider makes about your health status – obtaining a diagnosis, developing a course of action for treatment, or monitoring your body's response to therapy – are based on laboratory data.
Your provider trusts the results coming from the lab. That trust is well placed. Clinical laboratory testing is held to very high standards.
A test method must meet scientifically rigorous criteria before it can be used in clinical practice. In the U.S., the Food and Drug Administration (FDA) reviews the scientific evidence that:
- the test is able to detect or measure the substance it claims to detect or measure, and
- the measurement or detection of this substance provides important information about an illness or about health status that assists in the diagnosis, treatment, or monitoring of a patient.
A laboratory must demonstrate that it is able to perform that test in a clinically acceptable way. State and federal regulatory agencies monitor the laboratory and set standards that a laboratory must meet in order to be allowed to perform the test. Some of these standards are:
- Laboratories must conduct routine quality control tests, usually every day, to assure that the test method and equipment are performing to standards.
- Laboratories must participate in proficiency testing programs. For proficiency testing, an external agency sends challenge samples to be tested. The laboratory must report results back to the agency. The laboratory must get the right result in order to be allowed to continue to test patient samples. If the lab repeatedly fails to get the right result, it is prohibited from continued performance of that test until it can demonstrate that it has corrected the problems that led to the unacceptable results.
- Laboratories must demonstrate that they have policies and procedures in place to help assure that the sample is collected and handled in an appropriate way and that results are reported with information to help with interpretation of the result.
These requirements ensure that the tests performed by clinical laboratories for patient care will produce results that can be trusted.
Some of the statistical indicators that are used to assure that both the test method and the laboratory performing the test are meeting acceptable standards are described in the next few pages, along with descriptions of other ways in which laboratories assure reliability. In addition, the following links to other articles on Lab Tests Online provide additional details on specific concepts and practices that contribute to the trust placed in laboratory tests.
