General Laboratory Flashcards
What do Quality Assurance Programs usually involve?
- Regular checks for all instruments and equipment
- Making sure all parts are in working order and are performing as expected
- Monitoring of of specimen collection and labeling
- Review of all laboratory supplies, equipment, and water
- Assurance of all laboratory results and analyses
- Participation of external survey programs
What is a Standard?
A material, that has a known composition and a high degree of purity, and are usually described by its chemical and physical character.
What are Standards used for?
To identify and describe other materials or samples.
What is a Control?
A substance that contains known concentrations and amounts of the materials that will be measured in a particular test. (Will often have a chemical and physical character that is similar to samples being tested.)
What steps do you take when there are out of control test results?
- Check any and all calculations that have been made
- Visually inspect all reagents that have been used
- Inspect all instruments and equipment that were used
- Rerun a set of test with a new sample of the control
What steps should you NOT take when there are out of control test results?
- Inform the doctor of the out of control results
- Change batches of standards or reagents used
What does CLSI stand for?
Clinical and Laboratory Standards Institute
What does CLSI do?
Provides standards for a wide range of performance and testing. They cover all types of laboratory functions and microbiology.
What standards does CLSI provide?
- Labeling
- Security/Information technology
- Toxicology/Drug testing
- Statistical quality control/Quantitative measurements
- Performance Standards for various types of antimicrobial susceptibility testing.
CLSI Labeling standards
2 in x 1 in and contain the required elements; patient name (in upper left corner), unique identifier, birth date, date and time of collection, and collector’s signature or ID
CLSI Security/Information technology standards
Technical operational and implementation requirements for ‘in vitro’ analytical equipment and data management mist be followed and essential elements included and de-identification practices utilized.
CLSI Toxicology/Drug testing standards
Protocols for collecting, analyzing, interpreting, and reporting results of drug testing should be used as the basis for development of procedures.
CLSI Statistical quality control/Quantitative measurement standards
Provides guidance for quality control of different measurements procedures to ensure accuracy and safety of laboratory personnel.
Measures to ensure Quality Control
- Checking all the equipment is working properly
- Check for proper instrument handling
- Ensuring that appropriate organisms are used for sensitivity testing
- Double-checking negative reports (especially in parasitology) by supervising personnel
- Evaluating processing time to ensure samples are tested within the appropriate window
- Correlating results, such as reviewing both hemoglobin and hematocrit
- Maintaining accurate and appropriate records
- Preparing a quality control chart
- Establishing standards and controls for daily laboratory operation
- Establishing standards and protocols for acceptance or rejection of samples and analysis
- Applying Westgard’s rule to determine acceptable variation in control before rejecting test results
- Determining is a run has occurred to indicate results are out of control and should be rejected
When does a Shift occur on a Quality Control Chart?
- When the control values on a quality control chart appear to have changed suddenly.
- When control values on the chart are consistently being higher or lower than the mean value (w/in 2SD) on several says in a row.
When does a trend occur on a Quality Control Chart?
- A gradual or slow change in control values over a time period of several days.
What could cause an Upward Shift?
Change in a new standard that has a lower concentration than what is required for the particular test being performed.
What could cause an Downward Shift?
The change to a new standard that has a higher concentration than what is required for the particular test being preformed.
What could cause a trend on a quality control chart?
A slow deterioration or breaking down of an instrument, piece of equipment, or a reagent, and can be wither downwards or upwards.
When it comes to statistical terminology what does Accuracy refer to?
The ability of a test to obtain a true (or accurate) result.
What are Random Errors?
Any departures from the true or accurate value. They can be caused by errors that are inherent in all laboratory analyses and test and the exact causes are not able to be determined.
When it comes to statistical terminology what does Precision refer to?
Reproducibility of results obtained from a particular test. If a repeated test provides the same results time after time, then there is said to be a high degree of precision.
What is Standard Deviation?
A value that estimates the random errors that are inherent in any test or analytical procedure.
What does Standard Deviation do?
It gives insight into how much the obtained data values deviate form the mean (or average) value.
What is Variance?
The value of standard deviation multiplied by itself (square of the standard deviation). Similar to the standard deviation, it measures how obtained data values are spread around the mean (or average) value.
What does it mean to have a false positive?
That the presence of disease is detected when there is in fact no disease.
What does it mean to have a false negative?
That the results indicates that no disease is present when it actually is.
What does test sensitivity measure?
A screening test’s ability to correctly identify the presence of a disease, by using a ratio of tests with positive outcomes to the total number of affected (true positive) patients tested.
What does test specificity measure?
A screening test’s ability to correctly identify the absence of disease.
What is required for a test to have a high predictive value?
Both high sensitivity and high specify.
What is is called when a test is positive and the patient has acquired a disease?
True-Positive (TP)
What is is called when a test is positive but the patient does not have the disease?
False-Positive (FP)
What is is called when a test is negative, and the patient does not have the disease?
Ture-Negative (TN)
What is is called when a test is negative, but the patient does have the disease?
False-Negative (FN)
What is the following ratio represent?
TP/(TP+FN)
Level of sensitivity in testing: probability of a positive test result when a patient has the disease.
What is the following ratio represent?
TN/(TN+FP)
Degree of specificity: the probability that a negative test truly indicates a disease-free patient.
What is the ratio used for the Positive predictive value?
TP/(TP+FP): the probability that a test will produce positive results for patients who have a disease
What ratio is used to denote the probability that no disease exists in patients testing negative, or the Negative predictive value?
TN/(TN+FN)
What does it mean to provide total quality management (TQM)?
The commitment to meeting the needs of the customers at all levels within an organization. Promotes continuous improvement and a dedication to quality in all aspects of an organization.
What should one seek to provide TQM?
- Information regarding customer’s needs and opinions
- Involvement of staff at all levels in decision making, goal setting, and problem solving
- Commitment of management to empowering staff and being accountable through active leadership and participation
- Institution of teamwork with incentives and rewards for accomplishments
- The focus of TQM is on working together to identify and solve problems rather than assigning blame through an organizational culture that focuses on the needs of the customers
What emphasizes the organization and systems and processes within that organization rather than individuals?
Continuous Quality Improvement (CQI)
What are the steps to CQI include?
- Forming a knowledge team
- Identifying and defining measures used to determine success
- Brainstorming strategies for change
- Plan, collect, and utilize data as part of making decisions
- Test changes and revise or refine as needed
