A coagulation result can be analytically correct on the analyzer and still appear incorrectly in the final laboratory report. A unit may be missing, an inequality sign may disappear, a flag may fail to trigger review, or a repeated result may overwrite the wrong record. Interface verification therefore belongs in method implementation alongside calibration, QC, and specimen workflow checks.
The WHO laboratory information-management guidance identifies accurate data recording and transmission as part of the laboratory quality system. For a coagulation service, a practical verification plan follows a result from its source instrument through any middleware to the laboratory information system (LIS) and the report actually viewed by the requester.
Map the complete result pathway
Document each system that receives or transforms the result. Identify where test codes are translated, units are assigned, reference information is attached, calculations occur, and release rules are applied. The instrument display, middleware record, LIS screen, printed report, and clinical portal may not present identical fields.
Assign an owner for each configuration and a coordinator for the overall acceptance. Analyzer application specialists, LIS staff, and laboratory supervisors need a shared test record. A statement that the interface is connected establishes communication, but does not establish that every reportable result is represented correctly.
Verify test identity and specimen matching
Check each assay code independently. PT seconds, INR, APTT seconds, fibrinogen, TT, D-Dimer, FDP, and antithrombin results must reach the intended report fields. Similar names and panel abbreviations can conceal incorrect mappings. Confirm how orders, added tests, cancelled requests, and results without matching orders are handled.
Use controlled test identifiers rather than real patient details when exercising exceptional scenarios. Include barcode formats used locally, accession prefixes, leading zeros, and identifiers of different permitted lengths. Check that a secondary aliquot retains the correct association with its source request. The verification record should show both the transmitted identifier and the destination record.
Confirm units and numerical presentation
For every assay, document the source unit, destination unit, decimal precision, and any deliberate conversion. Verify the value before and after conversion using known examples. Do not assume that software labels imply the same measurement convention, particularly when changing an assay or analyzer application.
D-Dimer reporting deserves explicit review of the assay’s declared unit convention, including whether results are expressed in FEU or DDU. Fibrinogen and other quantitative assays also require consistent units across results, reference information, and comments. Preserve the method’s reporting convention; a numerical adjustment cannot establish equivalence between different assays.
Exercise boundaries, not only normal results
A few ordinary results are insufficient to test the interface. Include low and high reportable values, results outside the measuring interval, and the textual or coded outcomes the instrument can generate. Check greater-than and less-than signs, nonnumeric messages, missing results, and results with no clot detected where relevant to the application.
An unavailable or invalid result must not become a numeric zero or an apparently valid blank. Confirm that the report communicates the intended limitation and that exceptional results reach the appropriate review queue. Where live analytical materials cannot reliably generate a particular condition, use approved interface test messages under a controlled test procedure and identify them as simulations.
Check flags and review rules
Document which analyzer flags are transmitted and what the receiving system does with them. Some flags require withholding a result, others prompt manual review, and others provide information without preventing release. The intended behavior should be approved by the laboratory and consistent with the application instructions and local procedures.
If automatic release is used, test both cases that should pass and cases that should stop. Include combinations of flags and values, unavailable QC status, incomplete panels, and any local repeat or delta-check conditions. Interface testing should demonstrate the approved rules; it should not introduce new clinical thresholds without the laboratory’s normal review process.
Follow dilutions and repeated measurements
Determine where a dilution factor is applied. Some systems transmit an already corrected concentration, while others require a defined calculation downstream. Verify that the factor is neither omitted nor applied twice. Record whether the final report needs a dilution comment and how that comment is generated.
For repeat testing, confirm which result becomes final, whether previous measurements remain traceable, and who can select or amend the released value. Test manual dilutions, automatic repeats, and additional testing only where those workflows are supported. A technically successful transmission should not silently overwrite an authorized result.
Test interruption and recovery
Temporarily interrupt communication within an agreed test window and confirm how messages are queued, retried, acknowledged, and reconciled. Check for lost or duplicate results when the connection returns. Verify that late messages are attached to the correct request and that their timestamps are understandable.
Review the manual fallback procedure as part of this exercise. Staff need a controlled way to record results, communicate urgent information under local policy, and reconcile entries after recovery. Retain an audit trail showing which results were entered manually and how their accuracy was checked.
Approve the report that users receive
Acceptance should include the final printed or electronic report, not only the LIS work screen. Check that assay names, units, inequalities, reference information, method notes, and authorized comments remain visible and correctly associated. Long comments and narrow report columns can create problems that are absent from the instrument view.
Retain representative source records, received messages, final reports, expected outcomes, observed outcomes, and approval. Define which changes require targeted reverification, including software updates, test-code edits, unit changes, application revisions, or new middleware rules.
For distributors and manufacturers, useful installation support includes clear interface specifications and representative message examples. The laboratory can then verify its own reporting pathway with evidence. Reliable connectivity is achieved when the result, its identity, and its qualifications reach the requester together.