Quality Control in Clinical Chemistry

Flashcards covering key concepts from the 'Quality Control in Clinical Chemistry' lecture notes.

What is Quality Control (QC)?

Part of quality management focused on fulfilling quality requirements, involving systematic monitoring of analytic processes to detect errors.

What is the purpose of Quality Assurance (QA)?

To provide confidence that quality requirements will be fulfilled.

What are control limits in Quality Control?

Expected values represented by intervals of acceptable values with calculated upper and lower limits, typically set at ± 2 standard deviations from the mean.

What is the difference between Quality Control and Quality Assurance?

Quality Control identifies when an error has occurred, while Quality Assurance focuses on preventing errors from occurring.

What are the statistical concepts in Quality Control?

Key concepts include arithmetic mean, standard deviation, variance, and coefficient of variation.

Define 'Accuracy' in Quality Control terms.

The extent to which a measurement approximates the true value of the quantity being measured.

What is 'Precision' in Quality Control terms?

Also known as reproducibility; the degree to which repeated results agree with each other.

What is 'Specificity' in the context of Quality Control?

The ability of a method to detect a particular substance without interference from others present in the sample.

What is 'Sensitivity' in Quality Control?

The ability of a method to detect even the smallest amounts of a particular substance.

What is the main function of a 'Quality Control Surveillance System'?

To detect problems and establish norms that must be met.

Define 'Quality Control Corrective System'.

A system that offers education about errors and provides a program to remedy defects.

What are the components that can influence Quality Control parameters?

Standard materials, controls resembling unknown specimens, analytical methodologies, and procedural documentation.

What is the purpose of an Ideal Quality Control Material?

To ensure it resembles human samples, is inexpensive, stable over time, has no communicable diseases, and has a known analyte concentration.

What is a Levey-Jennings Chart used for?

Graphically represents control results over time to identify random and systematic errors.

What are 'Trends' in Quality Control results?

Series of values that continue to increase or decrease for at least six consecutive days, indicating potential reagent deterioration.

What does an Outlier indicate in Quality Control?

A control value that goes beyond +/- 2 standard deviations, suggesting random or systematic error.

What should be included in laboratory policies and procedures manual?

Standard operating procedures that should be revised annually.

What is the main cause of clerical errors in laboratory settings?

Mistakes made during the documentation process, such as incorrect labeling or calculations.

Describe the 'double beam spectrophotometer'.

A spectrophotometer that permits automatic correction of sample and reference absorbance to improve accuracy.

What is the role of a Monochromator in a spectrophotometer?

To isolate specific wavelengths from a light source before they reach the sample.