Analysis Flashcards
What are reference ranges?
A set of values within an upper and lower limit of a lab test
The mean +/- 2 s.d.
A set of values which represent the values found in 95% of people in the reference group
How is a reference group set up?
A large population >120 healthy people are tested
The mean of the results ans s.d. is calculated
What is standard deviation?
A measure of precision
It reflects the spread of values from the mean value
What is %CV?
Coefficient of variation
The s.d. expressed as a percentage of the mean
What is bias?
A function of the calibration process
A percentage reflecting the difference between the measured value and the tube
How is bias calculated
)(Target result - actual result) / target result) x 100
What is analytical sensitivity
The ability of the analyte to correctly identify the percentage of patients having a particular condition
The smallest amount of a substance that can be accurately measured
What does value non linear mean
The value exceeds the linearity of an assay and should be rerun on dilution
The analytical performance of a method is based on what four parameters?
Sensitivity
Precision
Linearity
Interference
Give examples of pre-analytical error
Wrong test ordered
