Quality Assurance Flashcards
Define Quality Control
- refers to operational techniques that must be included during each assay run to verify that the requirements for quality are met with
Define Quality Assurance
- refers to planned & systematic activities that provide confidence that the results given out by the lab are correct
What are the objectives of a biomedical lab?
to produce results that both clinicians and lab staff have confidence in
What is the purpose of QA ?
- maintaining the overall quality of patient results at pre-analytic, analytic and post-analytic stages
What are the 8 areas of concern for QA & lab management in Clinical Pathology Accreditation ?
- organisation & quality management system
- personnel
- premises & environment
- equipment, info systems & reagents
- pre-examination process
- examination process
- post-examination phase
- evaluation & QA
Describe the Assessment of Quality systems
- internal
- external
- schematic way –> external quality assessment scheme (CPA)
What are the objectives of quality in the lab ?
- support provision of high quality healthcare
- reduce morbidity/mortality
- reduce economic loss
- Ensure credibility of lab
What are some consequences of poor quality?
- inappropriate action = over-investigation, over-treatment & mistreatment
- inappropriate inaction = lack of investigation & no treatment
- delayed action
- loss of credibility
Define pre analytical variability
errors which occur when non analytical factors change the conc. of the analytes
What are some examples of pre-analytical errors?
- patient preparation
- specimen transport
- turnaround time
- patient identification
What is the purpose of clinical testing ?
- help establish a diagnosis where treatment & prognosis can be based
- determine mechanism of disease
What professional staff are involved in quality control ?
- lead consultant
- biomedical scientists
- clinical scientists
What percentage of patients require a lab test to aid in diagnosis ?
over 70%
Describe HCG as a marker for cancer
- mainly used to detect pregnancy
- also a marker for trophoblastic tumours of placental/germ cell origin
Why might HCG measurements be subject to false positives ?
due to the presence of Human Anti-mouse Antibodies (HAMA’s)
What are some examples of random errors (imprecision)?
- pipetting error
- temperature error
- mixing defect
What are some examples of systematic error ? (inaccuracy)
deterioration of ;
- control material
- calibrator
- reagents
How are internal quality control ranged calculated?
- calculated from a minimum of 20 data point from 20 separate days
- provisional values should then be reviewed once long-term data has been obtained
- acceptable ranges should be determined based on required quality of assay
define the 1 2s rule
One control results falls outside the +2SD
- no cause to reject run
Define 2 2s rules
- it detects systematic errors
- violated when 2 consecutive readings exceed the mean by 2SD on the same side
Define the 4 1s rule
4 consecutive readings of 1 control that exceeds + 1SD of the mean
Describe the 10 x rule
- reject run when 10 consecutive control runs occur on the same side of the mean
Describe UKAS
- United Kingdom accreditation service
- provides evidence that lab complies with best practices, its competent to undertake analysis & actively engaged in QA & QC
What does an ISO 15189 accreditation say about a lab?
- technical competence of staff
- quality assurance of data
- acceptable turnaround time
- traceability of measurements and calibrations to relevant standards
