QUANTITATIVE TESTS Flashcards
are substances that contain an established amount of the substance being tested- the analyte.
CONTROLS
solutions with specified defined concentrations that are used to set or calibrate instruments, kit or system before testing is begun.
CALIBRATORS
solutions with specified defined concentrations that are used to set or calibrate instruments, kit or system before testing is begun.
STANDARD
types of sources of control material
- FROZEN
- FREEZE - DRIED / CHEMICALLY PRESERVED
- ASSAYED CONTROLS - predetermined target value
- UNASSAYED / IN-HOUSE
repeated measurements
CENTRAL TENDENCY
three measures of central tendency are:
- MEAN
- MEDIAN
- MODE
the number that occurs most frequently.
MODE
the central point of the values when they are arranged in numerical sequence.
MEDIAN
the arithmetic average of results.
MEAN
one or more data points appear to be too high or low for the set of data, they should note included when calculating QC.
OUTLIERS
the closeness of the measurements
ACCURACY
the amount of variations in the measurements
PRECISION
square root of the sum of the squared differences of each data point from the mean divided by n-1 for samples
STANDARD DEVIATION
SD of a set of data points divided by the mean result expressed as percentage or as decimal points.
COEFFICIENT OF VARIATION
are control charts used to plot quality control values against previously set limits to determine if a procedure is in or out of control
LEVEY-JENNINGS (L-J) CHARTS
Two types of Error
- RANDOM ERROR
- SYSTEMATIC ERROR
occurs at any time and place within the testing or service process. This type of error generally does not reflect a failure in some part of the testing system.
RANDOM ERROR
occurs in a consistent direction or pattern. It indicates some failure in the system that can and should be corrected
SYSTEMATIC ERROR
when control is on the same side of the mean for five consecutive runs
SHIFT
when control is moving in one direction and appears to be heading toward an out of control value.
TREND
served as criteria interpreting the values that are plotted in Shewhart Levey-Jennings Chart
WESTGARD RULES
