Quality Control Flashcards
(53 cards)
An all inclusive / comprehensive system monitoring the accuracy of test results where all steps before, during and after the testing process are considered
Quality Assurance/Assessment (QA)
Provides a structure for achieving lab and hospital quality goals
Quality Assurance/Assessment
Processes considered in QA
pre-analytic, analytic and post analytic factors
monitor the analytical process; detect and minimize errors during the analysis and prevent reporting of erroneous test results.
Quality control
It uses statistical analysis of test system data
QC
example of published rules in Quality control
Westgard rules
TYPES OF QC: Daily
Internal
TYPES OF QC: Proficiency Testing
External
Determination of laboratory testing performance by means of intralaboratory comparisons
Proficiency testing
Must be integrated within routine workload and analyzed by personnel who are running the tests.
Proficiency testing
Used to access employee competency
Proficiency testing
Pre-Analytical & Analytical Causes of Error on 1. Samples under Sample Integrity
Lipemia
Hemolysis
Interfering Substances
Clotting
Incorrect tube
Post Anaytical Causes of Error
Incorrect reference ranges
Physician not notified of a panic or critical value
Incorrect interpretation of lab results by physician
Incorrect data entry of lab result
used to determine the lines of ‘normal’ and ‘acceptable’.
Statistic
a branch of mathematics that collects, analyzes, summarizes and presents information about “observations.”
Statistics
A statistical analysis of lab test data can help us define (2)
reference range for patients
Acceptable ranges for control specimen
the mathematical average of a group of numbers, determined by adding a group of numbers (events) and dividing the result by the number of events
Mean (x̄)
determined as the ‘middle’ of a group of numbers that have been arranged in sequential order. That is to say, there are an equal number of numbers on either side of the ‘middle’ number. In an odd # of observations, it is the _____ observation. In an even # of observations, average the ______.
Median - middle - two midde values
the number that appears most frequently in a group of numbers. There can be more than mode, or none at all.
Mode
Characteristic “bell-shaped” curve
Gaussian/Normal Distribution
All values are symmetrically distributed around the mean. This also assumed for all quality control statistic
Gaussian/Normal Distribution
refers to the ability to get the same (but not necessarily ‘true’) result time after time.
Precision
An accurate result is one that is the ‘true’ result.
accuracy
The degree of fluctuation in the measurements is indicative of the ___ of the assay.
precision
