Troubleshooting / Common Issues
One instrument consistently fails (|Error Index| > 1.0) across multiple specimens
Possible causes
- –Calibration drift on the failing instrument — calibration may be due or may have been performed incorrectly
- –Reagent lot difference — the failing instrument may be using a different reagent lot than the others
- –Instrument-specific maintenance issue — contamination, cuvette degradation, or lamp aging
- –Incorrect TEa or bias allocation configuration in Lab Settings
Recommended action
Review the Error Index by Instrument plot to confirm that failures are concentrated on one instrument and not specimen-specific. Check calibration records, reagent lot numbers, and maintenance logs for the failing instrument. Recalibrate if needed and repeat the affected measurements before drawing conclusions.
Error Index magnitudes increase at higher concentrations (fan-shaped pattern)
Possible causes
- –Percentage-based TEa is being applied correctly — absolute allowable error widens with concentration, so this is expected behavior in TEa terms
- –Proportional bias — the instrument's results are systematically higher or lower than the target by a consistent percentage
- –Linearity differences between instruments at higher concentrations
Recommended action
Review the scatter plot to distinguish between proportional bias (consistent directional offset) and non-linearity (curved pattern). If the Error Index values still exceed 1.0 at high concentrations despite percentage TEa, investigate the instrument's linearity verification data and calibrator traceability at upper range levels.
Coverage ratio is very low
Possible causes
- –Study specimens are clustered at a narrow concentration range rather than spanning the reportable range
- –The configured reportable range is much wider than the concentration levels actually tested
Recommended action
A low coverage ratio means inter-instrument agreement was only evaluated at a limited portion of the clinically relevant range. Consider adding specimens at concentrations covering the low, mid, and high ends of the reportable range before concluding that instruments are interchangeable across the full AMR.
Module is unavailable or fewer than 2 instruments appear in the configuration dropdown
Possible causes
- –Fewer than two instruments have been configured in Lab Settings
- –Instruments exist in Lab Settings but are assigned to a different lab area than selected
- –The analyte has not been added to the instruments in Lab Settings
Recommended action
Navigate to Lab Settings and confirm that at least two analyzers are configured under the same lab area with the relevant analyte added to each. The MIMC module requires a minimum of two instruments to be pre-configured before a study can be created.
One specimen's result appears to be an outlier on the scatter plot
Possible causes
- –Sample integrity issue — wrong specimen, mislabeled aliquot, or compromised sample
- –Data entry error — incorrect value recorded for that specimen on one instrument
- –Instrument error during that specific measurement — check the instrument's event log for that run
Recommended action
Use the Sample ID Finder on the Error Index by Instrument plot to highlight all measurements from the suspect specimen across all instruments. If the anomaly is isolated to one instrument on one specimen, investigate a sample handling or data entry error. If all instruments show an unusual value for that specimen, the issue is more likely specimen-related. Do not exclude data without documented justification.