The-Case-of-the-Curious-QC

You're a Biomedical Scientist in the Biochemistry Pathology Lab. It's Monday morning, and you’re running routine tests on the new Abbott analyser. You’ve just come off a relaxing weekend — but your week is about to take an unexpected turn. Start of the Day As you log into the LIMS and prepare your QC run for the day, the analyser throws an alert: (text-colour:red)[QC High: Level 2 control out of range for ALT. Review required.] What will you do? A. [[Repeat the QC and see if it's a one-off issue]] B. [[Check the Levey-Jennings chart and rule of Westgard violations]] C. [[Ignore it]] — it’s only slightly out of range and patients are waiting

You rerun both Level 1 and Level 2 controls. This time, Level 2 is still out, and Level 1 is now borderline. The analyser flags the ALT assay. Do you: A. [[Escalate to a senior or duty scientist]] B. [[Open a reagent lot check – maybe it's a bad batch]] C. [[Try calibrating the analyser to correct it]]

Smart move. You open up the QC dashboard and notice that ALT has been trending gradually upward over the past 5 days — creeping outside ±2SD. <img src="levey_jennings_alt.png" alt = "Levey Jennings chart showing gradual upward trend" style = "width:450px;height:300px;"> Now a Westgard 2-2s and R-4s rule is triggered. <img src="westgard_rules.png" alt = "Westgard rules" style = "width:500px;height:300px;"> Do you: A. Hold all ALT patient results and alert the team → [[Escalate to a senior or duty scientist]] B. [[Send the EQA data for ALT to compare with peer labs]] C. Override and release results anyway – the shift is minimal → [[Ignore it]]

You dig through the fridge and find an older lot of ALT reagent. You run QC with it — and both Level 1 and Level 2 are within range. <img src="reagent_lot_comparison.png" alt = "Reagent Lot Comparison" style = "width:450px;height:300px;"> Do you: A. [[Stop using the new reagent lot immediately]] B. [[Run split-patient samples on both lots and compare]]

You inform your senior. They check the instrument logs, reagent lot, and QC history. The issue seems to have started with a new lot of ALT reagent introduced 6 days ago. You now need to: A. [[Run a parallel test on the backup analyser]] B. [[Contact the manufacturer]]

You recalibrate the analyser. QC is now closer to the target but still fails Level 2 for ALT. Do you: A. [[Repeat calibration with fresh calibrators]] B. Accept the result anyway and run patients → [[Ignore it]] C. Accept that it may be a reagent issue → [[Open a reagent lot check – maybe it's a bad batch]]

You log into NEQAS and pull the latest EQA report. Your lab's ALT value is outside the allowable performance limit compared to the peer group. <img src="eqa_mock_alt.png" alt = "EQA results" style = "width:500px;height:300px;"> Do you: A. Submit a non-conformity report and update your QMS → [[Contact the manufacturer]] B. [[Retest the last EQA sample with a different lot]]

You test QC and a few archived samples on the backup analyser — all results are within expected limits. You conclude that the issue is limited to the new reagent lot on Analyser 1. Do you: A. Report the batch issue and quarantine the lot → [[Contact the manufacturer]] B. Continue with the backup only until resolved → ''End: Issue Managed Successfully'' → //Would you like to restart? Back to [[START]] //

You contact the manufacturer and raise a batch quality issue. They confirm a known stability fault affecting ALT on some lots. You complete a non-conformance (NC) in Q-Pulse, detailing the QC failure and corrective actions. <img src="qc_investigation_flowchart.png" alt = "QC Investigation Flowchart" style = "width:500px;height:300px;"> ''Outcome:'' Lab compliance maintained, patient safety preserved, good documentation. Well done. ''THE END – You handled the issue correctly.'' //Would you like to restart? Back to [[START]] //

You test 5 random patient samples using both the old and new ALT reagent lots. The new lot under-reports ALT by ~20%. You update your findings in the NC report and send this to the manufacturer. In the meantime, you switch fully to the old lot. ''Outcome'': Data-driven decision with clear documentation. You're praised for your diligence during audit. ''THE END'' //Would you like to restart? Back to [[START]] //

You decided to ignore the QC and release results. Later that week, a consultant raises concern about a patient with normal ALT results, despite signs of acute liver damage. The lab director gets involved. ''Outcome: ''You’ve breached ISO 15189 standards. Investigation opened. You are removed from patient-facing duties pending retraining. //Would you like to restart? Back to [[START]] //

You recalibrate the analyser. QC is now closer to the target but still fails Level 2 for ALT. Do you: A. Accept the result anyway and run patients → [[Ignore it]] B. Accept that it may be a reagent issue → [[Open a reagent lot check – maybe it's a bad batch]]