A test panel is a predetermined group of
medical test
A medical test is a medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, or to determine a course of treatment. Medical tests such as, physical and visual exams, diagnostic imaging, genetic te ...
s used in the
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
and treatment of
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
.
Test panels (sometimes called profiles) are typically composed of individual
laboratory
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicia ...
tests which are related in some way: by the medical condition they are intended to help diagnose (
cardiac
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
risk panel), by the specimen type (
complete blood count
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide cytometry, information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cell ...
, CBC), by the tests most frequently requested by users (comprehensive chemistry profile), by the methodology employed in the test (viral panel by
polymerase chain reaction
The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) t ...
), or by the types of components included (urine
drug screen
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhalati ...
).
Advantages of diagnostic test panels over individual diagnostic tests
Test panels offer various advantages to laboratories performing the tests (labor efficiency, potential for automation and reduced costs through performing large numbers of the same kinds of tests each day) as well as to end users such as ordering physicians and hospitals (more comprehensive testing, rapid turn-around, and lower prices). The presence of several tests responsive to the same clinical condition may also increase the chances of detecting that condition.
Disadvantages of test panels
Among the disadvantages of test panels are the inclusion of diagnostically sub-optimal tests based upon commercial availability of test
reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
s, cost considerations, or compatibility with the testing instruments and methods. Another disadvantage is the fact that approximately 5% of the test results can be expected to fall outside the normal (
bell curve) range for purely statistical reasons. Thus, there is an expectation that the number of abnormal appearing results will increase with the number of tests in the panel (for
quantitative
Quantitative may refer to:
* Quantitative research, scientific investigation of quantitative properties
* Quantitative analysis (disambiguation)
* Quantitative verse, a metrical system in poetry
* Statistics, also known as quantitative analysis ...
tests such as blood glucose and total protein). For a typical twenty-test panel, there will be, on average, one or more of these apparent abnormal results.
The proportion of such apparently abnormal results may be even higher if the normal ranges printed on the report do not accurately reflect the
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
,
gender
Gender is the range of characteristics pertaining to femininity and masculinity and differentiating between them. Depending on the context, this may include sex-based social structures (i.e. gender roles) and gender identity. Most cultures u ...
or age of the patient. It is common for normal ranges for bodily fluid constituents to differ from the general population for very young or old patients, and in some cases (such as
hormones
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and beh ...
) for males versus females. Differences in those parameters between species are more the rule than the exception.
The statistical considerations typically do not apply for
qualitative (present or absent) tests, such as drug screens, unless the substance being tested for (e.g. drug) is actually present at a concentration near the
cutoff concentration.
{{DEFAULTSORT:Test Panel
Medical tests