Quality Assesment And Quality Control Flashcards
What organization established minimum QC for all high complexity testing in 1988
CLIA
What are active errors
Errors from healthcare worker to patient
What are latent errors
Errors from organization or lab design
What are some examples of active errors
Failing to ID patient, missing blood vessel in phlebotomy, errors with data entry, errors in instrument or computer
What are examples of latent errors
Staffing problems, information technology, equipment malfunction
What are the phases of testing process
Preanalytical
Analytical
Postanalytical
In what phase of test processing do most errors occur
Preanalytical and post analytical phases
What are some error improving strategies
Formal patient safety training, communication between staff and providers, quality improvement projects
What is the purpose of college of American pathologists (CAP) quality assessment considerations
Attempt to reduce and eliminate lab errors
What are the two major components of quality assessment program
1) non-analytical factors
2) analysis of quantitative data (qc)
What are some non analytical factors in quality assessment
Maintaining certification/having certified personnel, established lab policies (SOPs), lab procedure manual etc
How is quality control assessed by an outside body
They monitor every step of sample acquisition, processing and return
What is proficiency testing
Assessment process that tests unknown specimens from outside source to ensure lab test results
In proficiency testing how is accuracy determined
By comparing results across labs
What are the ranges of acceptance
1) out of range: failing proficiency test
2) failure once: recheck or re test
3) failure twice: lose ability to perform that form of testing
What isQC
Procedures to monitor the accuracy and precision of test performance over time to monitor system failure, adverse environmental conditions and variance in operator performance
What are the goals of QC program
Establish, maintain accurate and precise methods; determine level of precision; CLIA compliance
What are control specimens
Material or solution with known concentration of analyte being measured
For tests of moderate complexity what is different with QC
Preform and document using 2 levels of control material each day based on manufacturer or CLIA
Define accuracy
How close to test result is to true value
Define calibration
Comparing instrument reading to known constant
Define control
Substance with known value that should be tested same way as a patient with similar matrix of that sample
Define precision
Reproducibility of test result
Define quality control
Use of controls to test for accuracy and precision
What is reliability
Accuracy and precision
Close to true value and reproducible results
Define standards
Highly purified substances of known composition different from control
Define variance
Amount of change
Define sensitivity
True positives, no false negatives
The proportion of cases with a specific disease or condition that gives a positive result
Define specificity
True negative, no false positives
The proportion of cases with absence of the specific disease or condition that gives a negative test result
Assaying for sensitivity and specificity, what elements are needed
Tests positive (false)
Tests negative (false)
Disease present (positive)
Disease absent (negative)
How do you calculate sensitivity of a test
Sensitivity%= (true pos)/(true pos+false neg)
How to calculate specificity
%=(true neg)/(false pos+true neg)
What are some common avoidable causes of false pos and false neg
Use of test at inappropriate time, use of obsolete test, test with inherently poor sensitivity or specificity
