ITC IRMA TruPoint Blood Analysis System - Manual (Page 105)

7.9
Collecting Correlation Data:
1. Ensure that the Correlation option is “off” when collecting correlation
data.
2. Ensure that the reference analyzer is properly maintained prior to the start
of data collection to ensure accurate correlation.
3. Obtain at least 50 split-sample results for each analyte using the IRMA
TruPoint analyzer and the reference analyzer. For each split sample, use
the same syringe, the same analysis order, and perform both analyses
within 5 minutes of each other.
The measurement range over which the test method is assessed must
span the entire clinical range. In general, this range will extend from
below the normal range to substantially higher than the normal range.
4. Graph the reference analyzer results against the IRMA TruPoint analyzer
results for each set of values. Plot the results for each analyte separately.
Make the reference analyzer results the Y (dependent) variable; make the
IRMA TruPoint analyzer the X (independent) variable.
5. Perform a linear regression analysis on the results.
6. Delete any data points that are more than 3 standard deviations from the
regression line. Replace them with data acquired from additional split-
sample analyses and redetermine the regression line.
7. The slope and intercept values of the regression line are the factors used
for the analyzer-to-analyzer correlation function.
Activating/deactivating the correlation setting
1. Highlight Correlation from TEST SETTINGS
and press edit . An Attention message appears,
stating that adjusting correlation factors will
affect future patient test results. Press
ok .
2. Highlight the desired Product Type and press
edit .
3. Highlight ”on” or ”off” button and press next .
If ”on” is selected, go to “Establishing or
Changing Correlation Factors”.