MT POST key terms

The range of test results expected in a healthy population, usually spanning the central 95 percent of values, used to judge whether a patient result is normal or abnormal.

A result far outside the reference interval that may signal immediate danger to the patient and requires prompt notification of the responsible clinician, with the notification documented.

A quality rule that compares a patient's current result with a previous result for the same test and flags the specimen when the change exceeds a set limit.

A statistical measure of how widely values spread around their mean; in the laboratory it describes the dispersion of control results and underpins precision assessment.

The standard deviation expressed as a percentage of the mean, allowing precision to be compared across tests or analyte levels with different units and magnitudes.

A control chart that plots quality control results over time against mean and standard deviation limits so trends, shifts, and random error become visible.

A set of statistical rules, such as 1-2s, 1-3s, 2-2s, R-4s, and 4-1s, used to decide whether control results indicate acceptable performance or a run should be rejected.

An external program that sends unknown specimens to many laboratories and compares each laboratory's results with peer results to assess ongoing testing accuracy.

A broader interlaboratory comparison scheme, of which proficiency testing is one type, used to verify performance against other laboratories and identify systematic bias.

The process of adjusting an instrument using materials of known value so that measured signals correspond correctly to true analyte concentrations.

The ability of a method to detect small amounts of an analyte, often described by the lowest concentration that can be reliably distinguished from zero.

The ability of a method to measure only the intended analyte without interference from other substances present in the specimen.

Rupture of red blood cells that releases hemoglobin into the specimen, which can discolor serum or plasma and interfere with many chemistry and immunoassay measurements.

Refusal to test a sample that fails acceptance criteria, such as incorrect tube type, insufficient volume, unlabeled container, or gross hemolysis, with the reason documented.

A documented, unbroken record of who collected, handled, stored, and received a specimen, required for forensic, workplace, and other legally defensible testing.

The collection of blood by venipuncture or capillary puncture using aseptic technique, correct order of draw, and appropriate tube selection for the tests ordered.

The recommended sequence for filling blood collection tubes so that additive carryover between tubes does not contaminate specimens and invalidate test results.

A substance such as EDTA, citrate, or heparin added to a collection tube to prevent blood clotting so that whole blood or plasma can be analyzed.

The fluid remaining after blood has clotted and the clot has been removed, containing no fibrinogen and used for many chemistry and immunology tests.

Infection control practices applied to every patient regardless of diagnosis, including hand hygiene, gloves, gowns, and eye protection when exposure to body fluids is likely.

Barrier items such as gloves, gowns, masks, and eye shields worn to protect the worker from contact with blood, body fluids, and other hazardous materials.

Any biological material, including blood, tissue, and cultures, that poses a risk of infection to people or the environment and requires safe handling and disposal.

A puncture-resistant, closable, labeled receptacle used to discard needles, lancets, and other sharp items immediately after use to prevent needlestick injuries.

Accidental penetration of the skin by a used needle or sharp, requiring immediate first aid, reporting, and evaluation for post-exposure prophylaxis and follow-up testing.

The United States Clinical Laboratory Improvement Amendments, which set federal quality standards for laboratory testing and classify tests by complexity.

A simple test classified as low risk under CLIA and cleared for use by untrained operators, still requiring adherence to manufacturer instructions and good practice.

The United States Health Insurance Portability and Accountability Act, which protects the privacy and security of identifiable patient health information, including laboratory results.

The ethical and legal duty to keep patient information private and share it only with those who have a legitimate need to know for care or required reporting.

A patient's voluntary agreement to a procedure or test after receiving an explanation of its purpose, risks, benefits, and alternatives in understandable terms.

How close a measured result is to the true value of the analyte, reflecting freedom from systematic error or bias in the measurement process.

How closely repeated measurements of the same sample agree with one another, reflecting random error rather than closeness to the true value.

A white blood cell involved in immune defense; its concentration and differential distribution in blood help identify infection, inflammation, and hematologic disease.

The iron-containing protein in red blood cells that carries oxygen; its concentration is a primary measure for detecting and classifying anemia.

The percentage of blood volume occupied by red blood cells, usually obtained by centrifugation or calculated from red cell count and mean cell volume.

An estimate of how much blood the kidneys filter per minute, commonly calculated from serum creatinine and used to stage chronic kidney disease.

The elapsed time from specimen receipt or order entry to result reporting, a key operational and service metric monitored by laboratories.

A graded set of containment practices and facility requirements, from BSL-1 to BSL-4, matched to the risk of the infectious agents being handled.