6 min read · Updated 22 Aug 2026
Most laboratory errors are pre-analytical or post-analytical rather than analytical: wrong patient identification, wrong tube, sample handling problems, transcription mistakes and reports released before approval. The controls that matter most sit at collection and at release.
Identification at collection
The costliest error is attaching the right result to the wrong person, and it almost always originates at collection rather than at the bench. Labelling the tube at the point of draw, from a barcode generated by the system rather than written by hand, removes the window in which an unlabelled tube can be confused with another.
The wrong tube
A sample drawn into the wrong additive may still run and still produce a number, which is worse than a sample that obviously fails. Pairing each test with its sample type and vial colour at the point of collection is a cheap control against an expensive failure.
Transcription
Every manual copy of a value is an opportunity to transpose digits. Where results are entered by hand, entering once into the system that produces the report — rather than onto a worksheet and then into a system — halves the exposure.
The wrong reference range
A correct value judged against the wrong range produces a report that reads as normal when it is not. Ranges that resolve by age and sex automatically remove a judgement that would otherwise be made under time pressure by whoever is at the screen.
Release before approval
If approval is a convention rather than a permission, it will be skipped on the day the lab is busiest. Making release conditional on approval by a user who holds that right converts a habit into a control.
Errors you cannot investigate
When a result is questioned weeks later, the useful question is what changed, when and by whom. Without an audit trail of result edits and price changes, an investigation becomes an argument between recollections.