Lab QC software: Levey-Jennings charts, Westgard rules and EQAS in your LIS
Internal quality control (IQC) is the daily check that an analyzer is giving correct results before patient reports go out. PathLab Software keeps it inside the lab software instead of a separate spreadsheet: control values arrive from the analyzer or are typed in, Westgard rules are applied automatically, a rejected run stops patient sign-off on that analyzer until someone records what was done, and EQAS results are scored by SDI.
What does a Levey-Jennings chart look like in PathLab Software?
One chart per analyte and control level, drawn from the last 30 runs. Bands show ±1, ±2 and ±3 SD around the target mean; amber points are warnings and red points are rejections.
Glucose · L1 · Erba EM 200 · target 92 ± 2.8 mg/dL · sample data
Day 7: one value beyond +2 SD (1-2s warning, run accepted). Days 15–16: two consecutive values beyond +2 SD (2-2s, run rejected): glucose was recalibrated, a fresh control vial run, and the corrective action recorded before patient glucose results were signed.
Which Westgard rules are checked?
PathLab Software evaluates every QC value against the target's history and against other control levels run the same day on the same analyzer. Each rule can be switched off per target if your quality manual says so.
| Rule | Triggers when | Action in PathLab Software |
|---|---|---|
| 1-2s | One control beyond ±2 SD | Warning: run accepted, point shown amber, review the next run |
| 1-3s | One control beyond ±3 SD (random error) | Reject: patient sign-off blocked on that analyzer |
| 2-2s | Two consecutive controls beyond 2 SD on the same side, or two levels in the same run | Reject (systematic error) |
| R-4s | One control above +2 SD and another below −2 SD | Reject (random error) |
| 4-1s | Four consecutive controls beyond 1 SD on the same side | Reject (shift) |
| 10x | Ten consecutive controls on the same side of the mean | Reject (trend / bias) |
What happens after a rejection?
The run is flagged in red and the lab is notified. Results from that analyzer cannot be validated and signed until a pathologist or lab in-charge records the corrective action: for example recalibration, a fresh control vial, a new reagent lot, or a rerun of the patient samples since the last good QC. The acknowledgement, who made it and when stay in the QC log and the audit trail. A point that was clearly a handling error, such as the wrong level loaded, can be excluded from statistics with a reason; it is never deleted.
Where do the target mean and SD come from?
Start with the manufacturer's assigned values for the control lot. After 20 or more in-control runs, PathLab Software shows your own observed mean, SD and CV for each analyte and level and can switch the target to them in one step, with the old and new values recorded.
EQAS and proficiency testing, scored by SDI
External quality assessment (EQAS) compares your lab with others on the same blind sample. Log each EQAS sample when it arrives and your result when you submit; when the provider's report comes, add the assigned value and SD. PathLab Software calculates the standard deviation index, SDI = (your result − assigned value) ÷ SD, and marks it acceptable (|SDI| ≤ 2), warning (≤ 3) or unacceptable (> 3, root cause and corrective action required). Use your scheme's own criteria where they differ.
Each cycle shows how many analytes were acceptable, in warning or unacceptable, and EQAS results print on the monthly QC log alongside the Levey-Jennings charts, which is what assessors usually ask to see together.
| Analyte (sample data) | Ours | Assigned ± SD | SDI | Result |
|---|---|---|---|---|
| Glucose | 112 | 108.5 ± 3.9 | 0.90 | Acceptable |
| Cholesterol | 186 | 181 ± 5.6 | 0.89 | Acceptable |
| Creatinine | 1.42 | 1.31 ± 0.04 | 2.75 | Warning |
| Haemoglobin | 11.8 | 11.6 ± 0.3 | 0.67 | Acceptable |
How QC maps to your NABL (ISO 15189) evidence
Daily IQC records
Every control value with time, analyzer, lot, level, z-score, rule result and who entered it. The analyzer connector logs QC automatically when the control tube carries its QC barcode.
Corrective actions
Every rejection has a recorded root cause and action, signed off by a named pathologist or in-charge, with the time patient sign-off was released.
Monthly QC log
A printable log per month with Levey-Jennings charts, runs, violations, actions and EQAS results, with a reviewer signature line. Save it as PDF for the quality file.
Control lots and expiry
Control materials have lot numbers and expiry dates; the lab is reminded 15 days before a control lot expires so the new lot can be run in parallel.
EQAS / PT
Cycles, samples, results, assigned values, SDI and corrective actions in one list for the assessor.
Audit trail
Target changes, excluded points and acknowledgements are logged with old and new values, user, time and IP address.
NABL accredits laboratories, not software; your accreditation is yours to obtain. See the clause-by-clause status on the NABL software page, the NABL software checklist guide, and how analyzer interfacing feeds QC automatically.
What does QC cost in PathLab Software?
Internal QC, Westgard rules, sign-off blocking, EQAS logging and the monthly QC log are included in the Pro plan at ₹3,999 a month and in Chain at ₹7,999, plus GST, with no per-analyzer or per-analyte fee. For comparison, as of October 2026 CrelioHealth's US/Canada pricing page lists QC integration from its Optimized plan at $1,400 a month; prices change, so check with the vendor. A full feature comparison is on the comparison page.
Frequently asked questions
What is a Levey-Jennings chart in a pathology lab?
A Levey-Jennings chart plots each day's internal QC result for one analyte and control level against the target mean, with lines at ±1, ±2 and ±3 SD. PathLab Software draws one per analyte and level from the QC values you enter or the analyzer sends, so drifts and shifts are visible before patient results go out.
Which Westgard rules does PathLab Software apply?
PathLab Software applies 1-2s as a warning and 1-3s, 2-2s, R-4s, 4-1s and 10x as rejection rules, within a control level and across levels run the same day. Each target can switch individual rules off, for example if your quality manual treats 4-1s as a warning.
What happens when a QC run is rejected?
The run is flagged in red, the lab is notified, and patient results from that analyzer cannot be signed until a pathologist or lab in-charge records the corrective action, such as recalibration, a fresh control vial or a new reagent lot. The acknowledgement and action are kept in the audit trail and the monthly QC log.
Does PathLab Software record EQAS or proficiency testing?
Yes. Log each EQAS or PT sample with your result, and when the provider's report arrives add the assigned value and SD; PathLab Software calculates the SDI, marks it acceptable, warning or unacceptable and asks for a root cause and corrective action when it is out. Results are listed per cycle and printed on the monthly QC log.
Is QC included in the price?
Yes. Internal QC with Levey-Jennings charts, Westgard rules, corrective actions, EQAS logging and the monthly QC log are included in the Pro (₹3,999 a month) and Chain (₹7,999) plans at no extra cost. As of October 2026, CrelioHealth's US pricing page lists QC integration from its Optimized plan ($1,400 a month); check with the vendor.
Can QC values come straight from the analyzer?
Yes. Give each control tube a barcode such as QC-L1-2611 in PathLab Software; when the analyzer runs it, the connector's results are logged as QC for that material and level instead of being matched to a patient. Manual entry works for every analyzer and for kit-based methods.
Does this make my lab NABL accredited?
No. NABL accredits laboratories, not software, and your accreditation is yours to obtain. PathLab Software keeps the internal QC and EQAS records that ISO 15189 clause 7.3.7 (ensuring the validity of examination results) asks for, alongside the audit trail, validation and critical-value records.
Move your QC register into the LIS
Send us your control lots, levels and target values; we set up the targets and the QC barcodes on your analyzers during the free setup.