Two investigations every accredited laboratory runs, each with its worklist written for it.
LotWarden and EQAWarden are offline investigation software for ISO 15189 laboratories. LotWarden writes the investigation worklist for every reagent lot that arrives without being accepted. EQAWarden investigates an EQA result that deviates: it names the findings, ranks the likely causes with their evidence and orders the checks. In both, a person decides the outcome and signs it.
Four events, and what each application does when one happens.
| The event | What is produced | By |
|---|---|---|
| A lot arrives that is new, untested, awaiting sign-off or rejected | A line on the investigation worklist with the action required, worst first | LotWarden |
| Stock arrives expired, or the delivery fails its condition check | First place on the worklist with a quarantine or return action; condition failures flagged in red and audit-logged | LotWarden |
| An EQA result falls outside its allowable performance specification, or in the warning zone | Findings with their numbers, ranked causes, ordered checks and a suggested outcome | EQAWarden |
| A supplier recalls a lot | Everything that happened to the lot, across departments: received, put into use, removed, and by whom | LotWarden's lot history |
Every lot gets a verdict at the door. The ones needing attention get a worklist.
In Chemistry, LotWarden checks each received lot against the pre-acceptance register and gives it one of five verdicts. Only lots needing attention are listed.
| Verdict | What it means | Action on the worklist |
|---|---|---|
| Accepted | Approved, or pre-acceptance testing not required | None. Fine to use; counted, not listed |
| Awaiting sign-off | Testing complete, not yet signed | Chase the sign-off before use |
| Testing in progress | Pre-acceptance testing underway | Hold until accepted |
| Rejected | Failed acceptance | Quarantine |
| Not on register | A new lot | Initiate pre-acceptance testing |
The worklist is saved as a workbook for each delivery, with blank Investigated By and Outcome columns for the person who does the work. The full check is saved beside it. In other departments each new lot is flagged in the preview and confirmed for verification at the bench before anything is written. More: Lot acceptance.
From a deviating result to a signed outcome, in five steps that are all on screen.
EQAWarden reviews RCPAQAP chemical pathology surveys. Every step uses fixed, published rules. There is no AI, so the same survey gives the same findings every time.
- Score. Each result is scored against its allowable performance specification: the deviation divided by the allowed error. Up to two thirds is within, two thirds to one is a warning, above one is outside.
- Find. 58 finding rules test the result, the survey and the analyte's history: clerical screens such as unit and sample-swap errors, bias and drift across a series, the cycle regression, steps at lot changes, agreement with internal QC, and the method group.
- Rank. 21 possible causes are scored from the findings. Strong evidence counts three, moderate two, weak one, and evidence against a cause is shown beside the evidence for it.
- Check. Investigation playbooks give the checks to make, in order, for the leading causes.
- Decide and sign. EQAWarden suggests one of four outcomes: corrective action, investigate, acceptable and monitor, or acceptable. The reviewer chooses, writes the conclusion and signs with initials. The record is hash-chained.
More: every rule and its threshold, and the statistics behind them.
Was it the lot?
With the two applications linked, EQAWarden marks every reagent and calibrator lot change on the analyte's chart and tests for a step at each one, with the confidence of the lot link stated.
Or the calibration?
Internal QC from Bio-Rad Unity Real Time exports sits beside the EQA result, before and after the change on the same control lot, so a reagent lot effect and a calibration effect can be told apart.
Or a typing error?
Clerical screens run first. A result that fits a unit mistake or a swapped sample is named as that before anyone opens the analyser's maintenance log.
Trace a recalled lot in seconds, across departments.
Type a lot number or part of a name into LotWarden's lot history. It shows when the lot was received, from whom and by whom, when it was put into use and removed, and where it stands now: unopened, in use, expired on the shelf or removed. Each line names the log and row it came from. Lots stay findable after a new year's log replaces the old one.
What these investigations are not.
- Neither application is a general non-conformance or corrective action register. They cover investigations that begin with a lot or an EQA result.
- They do not investigate incidents, complaints or patient results, and hold no patient data.
- The pre-acceptance register cross-check is in Chemistry. EQAWarden covers RCPAQAP chemical pathology programmes with numeric results.
- Neither decides. A ranked cause is a suggestion with its evidence, and the wording says how strong that evidence is.
- LotWarden and EQAWarden are independent products, not affiliated with or endorsed by NATA, ISO or RCPAQAP.
Questions about investigation.
What does ISO 15189 require when an EQA result is unacceptable?
Clause 7.3.7.3 of ISO 15189:2022 expects the laboratory to review its external quality assessment results against set criteria, and where a result falls outside them, to investigate, act where patient results could be affected, and keep the record. The standard does not set the method of investigation. That is the laboratory's own procedure.
How does EQAWarden work out the likely cause of an EQA failure?
It applies 58 published rules to the result, the survey and the analyte's history, then scores 21 possible causes from the findings: strong evidence counts three, moderate two and weak one. The causes are shown in rank order with the evidence for and against each. It uses no AI, and the reviewer makes the decision.
What is a lot investigation worklist?
It is the list LotWarden writes at receipt of every lot that is not yet accepted: new, in testing, awaiting sign-off or rejected. Lots are listed worst first, each with the action required and blank columns for who investigated and the outcome. Stock that arrived expired is at the top with a quarantine action.
Can the software tell whether a reagent lot change caused a shift?
It can show whether results moved when the lot changed. With LotWarden's lot records linked, EQAWarden runs a step test at each reagent and calibrator lot change and puts internal QC beside it. Whether the lot is the cause is the reviewer's judgement, made with that evidence.
Is this a corrective action or non-conformance system?
No. It records the investigation and outcome for lots at receipt and for EQA results. A laboratory's general register of non-conformances, incidents and corrective actions stays in its quality management system.
Watch an investigation run on a demo survey.
Twenty minutes on a video call, on fictional data: a delivery with a new lot, then the EQA assessment that names it.