W11L14 - Assuring Quality of Examination Procedures Flashcards
Quality Control
Techniques and activities that are used to fulfil requirements for quality
Control Materials
A device, solution or preparation to use in the quality control process
Monitors the reliability of a test system and to maintain its performance within established limits
Internal Quality Control Materials
‘In house’ samples/serum/blood
Patient samples
Manufacturer/commercial QC
Internal Quality Control Selection
QC material used must cover the analytical concentrations encountered:
- low/normal/high
- normal/abnormal
- positive/negative
- reactive/non-reactive
Essential Considerations of Internal QC
Storage/expiry/stability - frequency of use
Volume required
Infection control
Precision
Closeness of agreement between independent test results from the same sample obtained under stipulated conditions
Accuracy
Closeness of the agreement between the result of a measurement and a true value of the measurand
Bias
Systematic error of the indication of a measuring instrument
Control Drift and Shift
Drift - controls gradually moving away from the mean over a period of time - control deterioration - reagent deterioration - instrument/calibration Shift - sudden change in a controls value - operator change/error - instrument/kit failure - incorrect control
External Quality Assurance Proficiency Testing
A program in which multiple samples are sent to members of a group of laboratories for analysis
Each laboratories results are then compared with those of other laboratories in the group
Key Requirements of QAP/QC
Must cover all testing performed
All lab staff must participate
Must review and act on QC results in a timely matter
QC acceptance procedures must be in place
Corrective actions taken and documented as required
