MT6316 CHAPTER 9 Flashcards
The accuracy, reliability and timeliness of reported test results
Laboratory Quality
T or F: Lab reported are still reliable if they are accurate but not realized or done in a timely manner
F
Negative consequences of laboratory error include?
- unnecessary treatment
- treatment complications
- failure to provide the proper treatment
- delay in correct diagnosis
- additional and unnecessary diagnostic testing
The negative consequences of laboratory error result in?
increased cost in time and personnel effort and often in poor patient outcomes.
Coordinated activities to direct and control an organization with regard to quality
Quality Management System
All aspects of lab operations within the organizational structure, processes and procedures which need to be addressed to assure quality
Quality Management System
Quality Management System is defined by?
ISO and CLSI
To assure quality in each phase of testing, what is needed?
A method of detecting errors
Complexity of the laboratory system requires that many factors must be addressed to assure quality in the laboratory, which include?
- the laboratory environment
- quality control procedures
- communications
- record keeping
- competent and knowledgeable staff
- good-quality reagents and equipment
What complexity is the focus of Quality Management System?
Quality control procedures
Defined by the WHO as a set of procedures for continuously assessing laboratory work and the emergent results
Internal Quality Control (IQC)
Internal Quality Control (IQC) may also be referred to as?
Quality Control
How is measurement of Quality Control done?
examining “control” materials of known substances along with patient samples to monitor the accuracy and precision of the complete analytic process
What phase of testing is quality control concerned with (mainly)?
examination (analytic) phase
What is the goal of QC?
to detect, evaluate, and correct errors due to test system failure, environmental conditions or operator performance, before patient results are reported
QC is applied to monitor?
- Quantitative examinations
- Qualitative examinations
- Semiquantitative examinations
measure the quantity of an analyte present in the sample
Quantitative examinations
measurements need to be accurate and precise and these produce a numeric value as an end-point, expressed in a particular unit of measurement
Quantitative examinations
measure the presence or absence of a substance or evaluate cellular characteristics such as morphology
Qualitative examinations
results are expressed as an estimate of how much of the measured substance is present
Semiquantitative examinations
How are Semiquantitative examination results expressed?
in terms such as “trace amount”, “moderate amount”, or “1+, 2+,3+”
urine dipsticks, tablet tests for ketones
Semiquantitative examinations
serologic agglutination procedure
Semiquantitative examinations
serologic testing result expressed as a titer (involves a number but provides an estimate, rather than an exact amount of the quantity present)
Semiquantitative examinations
microscopic examinations and serologic procedures for presence or absence of antigens and antibodies
Qualitative examinations
microbiological procedures
Qualitative examinations
Example: blood glucose
Quantitative examinations
Elements of a quality control program
- establishing written policies and procedures, including corrective actions
- training all laboratory staff
- ensuring complete documentation
- reviewing quality control data
Steps in implementing a quality control program
- establish policies and procedures
- assign responsibility for monitoring and reviewing
- train all staff on how to properly follow policies and procedures
- select good QC material
- establish control ranges for the selected material
- develop graphs to plot control values (Levey–Jennings charts)
- establish a system for monitoring control values
- take immediate corrective action if needed
- maintain records of QC results and any corrective actions taken
Laboratory practices on assuring quality include?
- Preventive
- Assessment
- Corrective
activities done prior to the examination of specimen or sample
Preventive
intended to establish systems conducive to accuracy in analytic systems
Preventive
Preventive measures include?
preventive maintenance and calibration of instruments, testing of media, orientation and training of personnel
activities done during the testing to determine whether the test systems are performing correctly
Assessment
Assessment includes the use of?
use of standards and control materials and maintenance of control charts
activities done when error or possible error is detected
Corrective
Anticipative action done to prepare the equipment for the general processes in the analysis of results
Preventive
Reactive measures taken when the error is already encountered
Corrective
Corrective action includes?
equipment trouble shooting, recalibration of instruments
substances that contain an established amount of the substance being tested—the analyte
Control Materials
Before running the sample, the machine or equipment should undergo what process?
Control material testing
Control materials are tested at the same time and in the same way as?
patient samples
What is the purpose of Control Materials?
- to validate the reliability of the test system
- to evaluate the operator’s performance and environmental conditions that might impact results
If the result of the control material is beyond normal range after running it, do you still run the patient sample?
No
Calibrators are also known as?
standards
Solutions with a specified defined concentration that are used to set an instrument, kit, or system before testing is begun
Calibrators
T or F: Calibrators can be used as controls
F, cannot be used as controls since they are used to set the instrument
T or F: Calibrators have the same consistency as patients’ samples
F, do not have consistency
Types of Control Materials
- Frozen
- freeze-dried (lyophilized)
- chemically preserved
Freeze-dried or lyophilized samples must be?
reconstituted, requiring great care in pipetting in order to ensure the correct concentration of the analyte
Examples of reconstitution reagents?
Buffer, reagent-grade water
During reconstituting, not pipetting the correct amount of reconstituting reagent will lead to?
Having the wrong amount of analyze
What form of control materials can be used readily?
Frozen
Chemically Preserved
Sources of Control Materials
- Purchased
- obtained from a central or reference laboratory
- made in-house by pooling sera from different patients
Types of purchased control materials?
Assayed
Unassayed
have a predetermined target value, established by the manufacturer
Assayed controls
Which is more expensive: Assayed or Unassayed controls?
Assayed
When using either unassayed or “in-house” controls, who must establish the target value of the analyte?
the laboratory
In choosing control materials, select values that cover ____________ – one with a __________ and one that is ___________
medical decision points
normal value
either high or low, but in the medically significant range
In establishing the value range for the control materials, determine the range of acceptable values for the control material to know if the test run is?
“in control” or “out of control”
How is establishing the value range for the control materials done?
by assaying the control material repeatedly over time
At least how many data points must be collected by how many days for establishing the value range for the control material?
20 data points
20-30 days
In establishing the value range for the control material, what needs to be calculated?
mean and standard deviation of the results
What is the purpose of obtaining 20 data points?
to quantify normal variation and establish ranges for QC samples
one or two data points that appear to be too high or low for the set of data
Outliers
If there is a presence among the 20 data points indicate a problem with the data, what should be done?
Data should not be included when calculating QC ranges.
commonly used to represent the control range graphically for the purpose of daily monitoring
Levey–Jennings Chart