Levey-Jennings Chart
Reading and interpreting the Levey-Jennings QC chart.
The Levey-Jennings chart is a graphical display of QC data over time. Kanta generates it automatically from your QC run history — no manual charting required.
Reading the chart
The chart plots each QC value on the Y-axis (measured result) against the run date on the X-axis. Control lines are drawn at:
| Line | Meaning |
|---|---|
| Mean | Your target value (solid line in the centre) |
| ±1 SD | Inner control lines — most results should fall here |
| ±2 SD | Warning lines — occasional values expected, but multiple consecutive values here trigger a warning |
| ±3 SD | Action lines — any single value beyond this is an immediate failure |
A well-controlled analyser produces a chart where values scatter randomly around the mean, mostly within ±2 SD.
Patterns that indicate problems
| Pattern | Likely cause |
|---|---|
| Trend — 6+ consecutive values moving in one direction | Reagent deterioration, calibration drift |
| Shift — 6+ consecutive values all above or below the mean | New reagent lot, calibration issue, control material change |
| Increased scatter — values spread widely across all SD levels | Instrument instability, mixed QC material |
| Single value beyond ±3 SD | Transcription error, pipetting error, control material problem |
Viewing the Levey-Jennings chart in Kanta
- Go to Quality & Samples → QC
- Click an analyser name
- Select the parameter (e.g. Haemoglobin, Glucose, ALT)
- Select the QC level (Normal / Abnormal High / Abnormal Low)
- The Levey-Jennings chart renders for the selected date range
Use the date picker to zoom in on a specific period. Failed runs are shown as red points; passed runs are green.
Printing for accreditation
Click Export chart (PDF) to download a clean version of the Levey-Jennings chart suitable for accreditation files (ISO 15189, KENAS, CAP, etc.). The export includes analyser name, parameter, QC material, lot number, date range, and all control line values.
For help, contact your Lab Manager or email [email protected].