Quality Management Flashcards
Systematic, integrated set of activities to establish and control the work process from preanalytical through postanalytical processes,
Quality management system
Preventive measure
Monitors performance starting from ordering to reporting
Quality assurance
Analytic phase-
Testing
Post analytic phase
Release of results
System of ensuring accuracy and precision in the laboratory
Quality control
Quality control is concerned only on the
Analytical phase
Process of ensuring that analytical results are correct by testing known samples that resemble patient samples→ known as
QC sample or control
both accurate and precise
Reliable
Is the ability of an analytical method to measure the smallest concentration of the analyte of interest
Sensitivity
It only measure the analyte of interest
Specificity
The nearness or closeness of the value to the true value or the target value
Accuracy
true value or the target value
Mean
- The ability of an analytical method to give repeated results to the same sample that agree with one another
- The values are near each other
Precision or reproducibility
The degree to which a method is easily repeated
Practicability
Able to maintain both accuracy and precision even over an extended period of time
Reliability
Ability of an analytical method to detect the proportion of individual’s WITH the disease
Diagnostic sensitivity
Ability of an analytical method to detect the proportion of individual’s WITHOUT the disease
Diagnostic specificity
Diagnostic specificity is able to detect
True negatives
Kinds of quality control
Interlab QC/ External QC
Intralab QC/ Internal QC
Involves proficiency testing (EQAS) programs that periodically provide samples of unknown concentration to participating clinical laboratories
Interlab QC/ External QC:
Proficiency testing
EQAS
- Analysis of control samples together with the patient specimens (within lab)
- This type of QC is able to detect both random and systematic errors
Intralab QC/ Internal QC
Intralab QC/ Internal QC can detect
Both random and systematic errors
your internal QC is run everyday, minimum number of samples in a month should be
20
Errors encountered in the collection, preparation and measurement of samples, including transcription and releasing of lab results
Variations
- Due to chance
-Can vary for sample to sample
Random error
- detected as positive or negative bias
- Often related to calibration problem, deteriorate reagent or control
Systematic error
Human error
Clerical error
Used to observe values of control materials over time to determine reliability of the analytical method
Quality control chart
Used to observe values of control materials over time to determine reliability of the analytical method
Quality control chart
This occurs when that data set is accurately described by your standard deviation
and your mean
Gaussian curve ( bell curve )
- Calculates the difference between QC results and your target means
- It can identify consistent bias problems
- Requires implementation computer
Cumulative sum graph
Compare results obtained on
a high and low serum from different laboratories
Youden twin plot
- Most widely used QC chart in
the laboratory
-Can observe a trend or a
shift or an outlier
Shewart Levey Jennings Chart
Shewart Levey Jennings Chart errors
Trend, shift, outlier
Is formed when control values increase or decrease for a minimum of 6 consecutive days
Trend
Cause of trend
Deterioration of reagents
This is formed when control values distribute themselves on one side of the mean for a minimum of 6 consecutive days
Shift
Cause of shift
improper calibration of the instrument
A control value that is far form the main set of values
outlier
more accurate SD
low SD
- dispersion of values
- how hey are far away from the mean, how close they are from each other (precision)
standard deviation
data that cluster about one point
central tendency
refers to raw data arranged in ascending (or descending) order
array
refers to the the interval between the largest and smallest value in the data set
range
tells how many times each value occurs
frequency distribution
is the measure of the degree of variance from a mean value
standard deviation
all the data are close to the mean
SD is small
are values that fall within the preset acceptable limits
confidence limits
is a substance with exact value and purity associated with it
standard
- is a substance with a particular value that has been determined by the manufacturer
- often used to adjust an instrument to certain values prior to running samples
- may be a standard or vice versa
calibrator
