Quality Control Flashcards
What is a quality management system
consists of all the processes that affect the quality of laboratory test results
What are the 12 components of a quality management system
- Quality improvement
- Organization and structure
- Personnel management
- Information management
- Occurrence management
- Process control
- Service and satisfaction
- Assessment
- Documents and records management
- Equipment management
- Purchasing and inventory
- Facilities and safety
What is quality assurance
all the activities implemented in a quality system so that quality requirements will be fulfilled and to assure the reliability of test results
What are preanalytical variables of quality assurance
test ordering, patient preparation and identification, specimen collection, transport of the specimen, handling of specimen prior to analysis
What are analytical variables of quality assurance
quality control procedures
What are post analytical variable of quality control
turn around time and reporting of results
What is quality control
the monitoring of a test procedure to ensure that the results are valid, accurate and precise
What is accuracy
reliability, refers to the closeness with which results check with the true value
How is accuracy assessed
- analysis of specimens containing known amounts of a substance and comparing results with the true value
- comparison of results with results from a reference method
- comparison with results obtained by a reference laboratory
What is a reference method
a method that is specific for the analyte and is very accurate, also referred to as gold standard
What is precision
the reproducibility of a method, the closeness with which several repeat results check with each other
How can precision be expressed mathmatically
with standard deviation or coefficient of variation
What is standard deviation
the measure of variability about the mean
What is the coefficient of variation
the expression of the standard deviation as a percentage of the mean
What is a primary standard
a reference material that has a known amount of analyte and is used for calibrating an instrument or preparing standard curves
What is a secondary standard
a reference material in which the analyte concentration has been determined by reference to a primary standard
What is a calibrator
a cell suspension whose parameters have been determined by multiple reference laboratories by reference methods in order to certify their assigned values
What is the only measurement in heme that is based on a standard
hemoglobin (cyan-methemoglobin standard)
What are the three requirements of a standard
- similar in composition to unknown samples
- analyzed in the same manner as unknowns
- stable
How are precision checks done in hematology
a specimen is loaded and ran 6 times then the coefficient of variation is determined
How are precision checks done in coagulation
two patient samples are pooled and then run 10 times the mean, SD and CV% are determined
What are computer delta checks
the computer compares current results with the most recent previous result. If it is significantly different as determined by pre-set limits then it fails the delta check and is flagged
What does a tech need to do in the case of a delta failure
check sample stability (ie. clot), labeling and patient history
What must a tech do in the case of a critical result
- Review testing conditions and specimen integrity
- Check previous results on the patient to see if previously critical
- Confirm the result
- Verbally report the results and document report
What is bulls moving average
used to monitor instrument drift since red cell indices stay relatively constant on average over time in a given population
What is a non-conforming event
any incident, error or near miss that does not conform to an established policy or procedure which affects lab results or patient care
What is an adverse event
when an error reaches the patient
What is a close call
when an error almost reaches a patient but is caught in time
What is a hazard
an event waiting to happen that has the potential to cause an error
What is a systematic error
a regularly occurring error that is measurable
What is a random error
accidental and unmeasurable
What type of error effects accuracy
standard
What type of error effects precision
random
