Accuracy you can evidence
Your result is compared against a consensus value derived from laboratories running the same method on the same instrument platform. A systematic offset that internal QC cannot see becomes a number you can act on.
Home / About EQAS
External quality assessmentWhy every pathology lab
needs an EQAS programme
External assessment is the only routine check that can detect a bias your own controls reproduce perfectly. Here is what it does, and how a cycle actually runs on your bench.
What external assessment adds
Internal quality control answers one question: is my analyser doing today what it did yesterday? External assessment answers a different one: is what it does correct?
Regulatory compliance
Participation in interlaboratory comparison is a documented requirement under ISO 15189 and a standing expectation in NABL assessment. The certificate and participation record exist for that file.
Continuous improvement
Twelve data points a year reveal drift that a single check cannot. Trend analysis across a cycle shows whether a deviation is noise or the early edge of a calibration problem.
Patient safety
A creatinine reading biased 8% high changes eGFR staging. A microalbumin bias changes who gets started on treatment. Accuracy at the bench is a clinical outcome, not a paperwork exercise.
Method and reagent decisions
When you evaluate a new analyser or reagent lot, a year of peer-referenced data tells you whether the change moved you toward or away from consensus.
Credibility with referrers
Consistent peer-referenced performance is a concrete thing to show hospitals, corporate clients and insurers who ask how you assure quality.
The cycle
Seven steps, twelve samples, one year
Enrolment to certificate. Nothing here needs a dedicated technologist — the samples run in your normal batch.
- 01
Enrol and receive your lab code
Register once for the year, choose your schemes, and declare the method and instrument used for each analyte. That declaration is what places you in the correct peer group.
- 02
Samples dispatched
Lyophilised serum or urine material ships with reconstitution instructions and a dated schedule showing which vial opens in which month.
- 03
Analyse as routine work
Reconstitute exactly as instructed and run alongside patient specimens — same operator, same calibration, same reporting units. Special handling defeats the exercise.
- 04
Submit before the closing date
Enter results in the participant portal. Late returns are recorded as non-participation for that month, and that is what an assessor sees in the end-of-cycle summary.
- 05
Statistical analysis
Outliers are trimmed, the consensus mean and SD are established for each method and instrument combination, and your bias and Z-score are calculated against that group rather than the whole cohort.
- 06
Report, review, corrective action
Your monthly report arrives within days of the closing date, showing whether a deviation is isolated or part of a trend — so root-cause investigation starts from evidence, not guesswork.
- 07
End-of-cycle summary and certificate
A twelve-month view of bias per analyte, your participation record, and a certificate suitable for a NABL application or surveillance audit.
Before you enrol
Questions laboratories ask
If yours is not here, write to us and we will answer it directly rather than send a brochure.
Will this satisfy our NABL assessor?
Participation records and the end-of-cycle certificate are prepared for exactly that purpose. Confirm the schemes you enrol in cover every analyte in your accreditation scope — gaps in scope coverage, not the certificate itself, are the usual finding.
What happens if we get an unacceptable result?
Nothing punitive. The report gives the size and direction of the deviation and whether it is isolated or trending. You investigate, document what you found and what you changed, and keep the record.
We use an uncommon method. Will there be a peer group?
Peer groups need enough participants to produce a meaningful consensus. Where numbers are too small, your result is compared against the all-method group and the report says so plainly, so you can interpret the bias correctly.
Can we join partway through a cycle?
Yes. You receive the remaining samples and your certificate reflects the months you took part in. Most laboratories time enrolment to the start of the cycle so the summary covers all twelve.
How is the sample material handled?
Lyophilised material ships with reconstitution instructions and storage conditions. Reconstitute with the stated volume, mix without foaming, and allow the stated equilibration time. Most unexplained outliers trace back to reconstitution, not to the analyser.
Who is the scheme for?
Any laboratory reporting the analytes covered — government hospitals, private laboratories and hospital chains, medical colleges, and corporate diagnostic networks. Participation is voluntary.
Enrolment for the 2026 cycle is open
Register a new laboratory or renew an existing participation. Already enrolled? Sign in to submit this month's results.