Legion Diagnostics

Troubleshooting / Common Issues

All specimens are marked Incorrect

Possible causes

  • –ISI entered in the study does not match the value programmed in the analyzer
  • –Normal Patient Mean PT entered in the study does not match the value programmed in the analyzer
  • –Analyzer was programmed with parameters from a different reagent lot
  • –Analyzer software was updated or reset and parameters were not re-entered

Recommended action

Access the analyzer's programming interface and record the ISI and NPM currently set in the instrument. Compare those values to the package insert ISI and the Geometric Mean & VRI report NPM for the current reagent lot. Correct whichever value differs and re-run the check.

Some specimens are Correct and some are Incorrect

Possible causes

  • –Data entry error — PT or INR values for the incorrect specimens were transcribed incorrectly
  • –Analyzer used a different rounding convention for some results (e.g., INR reported with fewer decimal places for some samples)
  • –The analyzer applied a different calculation path for outlier-range specimens

Recommended action

Re-read the analyzer printout or screen for the flagged specimens and verify that the PT and INR values were entered exactly as reported. Pay particular attention to decimal precision — a value entered as 1.3 instead of 1.30 may change the tolerance calculation. If the values are confirmed correct and still fail, investigate whether the analyzer applies any range-specific overrides.

Calculated INR differs from Analyzer INR by a consistent offset across all specimens

Possible causes

  • –The ISI entered in the study is slightly different from the ISI programmed in the analyzer (even a small difference compounds at elevated PT values)
  • –The Normal Patient Mean PT entered in the study differs from the programmed value

Recommended action

A systematic offset that is consistent across all specimens (rather than random differences) is a strong indicator that one of the two parameters is wrong by a fixed amount. Try adjusting the ISI or NPM by small increments to identify which parameter produces agreement when corrected. Then update the study to match the correct values and confirm with the analyzer's programming interface.

No results appear in the analysis table

Possible causes

  • –ISI or Normal Patient Mean PT has not been entered in the study design
  • –PT or INR values entered for specimens are zero, blank, or non-numeric

Recommended action

Verify that the ISI and Normal Patient Mean PT fields are both populated with valid positive numbers. Confirm that all specimen rows have valid numerical entries for both ProTime and INR.