Lab management Flashcards
What is standardisation?
Trueness based agreement
Comparable results with traceability to a primary reference standard
What is Traceability?
The unbroken chain of calibrations connecting a routine result to a primary reference standard
What is Harmonisation?
Consensus based agreement.
Comparable results without traceability to a primary reference standard
Formula for positive likelihood ratio
sensitivity / (1-specificity)
Formula for negative likelihood ratio
(1-sensitivity)/specificity
What is the Limit of Blank (LoB)?
Highest apparent concentration of analyte free material.
What is the Limit of Detection (LoD)?
Lowest concentration of analyte confidently measured
(Lowest concentration confidently separated from the blank)
What is the Limit of Quantitation (Functional Sensitivity)?
Lowest concentration of analyte reliably measured
What is the definition of Uncertainty of measurement? (as per ISO15189)
Parameter associated with the result of measurement that characterises the dispersion of values
What are the 6 steps of EBLM?
- Ask - frame a PICO question
- Acquire - search the literature
- Appraise - critically review the literature
- Analyse - systematic reviews and meta analyses
- Apply - develop and promote guidelines
- Assess - audit/evaluation
What does PICO question stand for in evidence based laboratory medicine?
Patient
Intervention
Comparator
Outcome
What does STARD stand for?
Standards for Reporting Diagnostic Accuracy studies
Formula for correcting sodium concentration for hyperglycaemia
Na (corrected) = Na (measured)+ Glucose/4
Calculation to estimate VLDL from triglycerides (using mmol/L)
Trig/2.2
Formula for creatinine clearance
(Urinary Cr x Vol)/(Plasma Cr x Time)
What calculations are available to estimate renal function?
Cockcroft and Gault
MDRD formula
CKD-EPI
In pre renal renal failure, what would you expect the fractional excretion of sodium to be?
<1%
Components of a patient based real time quality control system
Calculations algorithm
Block size
Truncation (filtering) limits
Control limits (or rules)
Method validation involves assessing… (name 8 components)
- Accuracy
- Precision
- LoD and LoQ
- Working concentration range (linear range)
- Standard measurement uncertainty
- Interference studies (specificity)
- Stability studies
- Establishing the reference range
Minimum scope for Method Verification
- intra-assay precision and accuracy
- inter-assay precision and accuracy
- correlation with existing method