Templates and records · ISO 15189 · Clause 7.3.5

ISO 15189 reference intervals and clinical decision limits

The values the doctor compares the patient's result against: where they come from, whether they suit the laboratory's population and when they were last reviewed.

In one sentence

The reference intervals and clinical decision limits record documents, for each measurand, the interval or limit used, its source — in-house study, literature, manufacturer, clinical guideline — the population it applies to, how its transferability was verified, its communication to users and its review, because clause 7.3.5 of ISO 15189:2022 requires them to be defined, their basis recorded and their review whenever the examination or pre-examination procedure changes.

Content reviewed on 17 October 2026

Where the standard requires it: ISO 15189 · Clause 7.3.5 Clauses are cited using the numbering of ISO 15189:2022, the edition in force since the transition ended in December 2025 and the same one the Academy uses.
Type of information: Mandatory document Intervals and limits defined, with their basis documented and communicated (7.3.5)
Who fills it in: Consultant responsible for each section With the agreement of the clinical services when decision limits are set
When: When each method is introduced And at every change of method, sample type or population served
How long it is kept: Set by the laboratory ISO 15189 asks for the retention time of each record to be defined, taking into account legal and user requirements (8.4). Those forming part of the medical record also follow the applicable health regulations.

What the standard requires

What ISO 15189 demands and what it leaves to your judgement

The standard requires the laboratory to specify biological reference intervals and clinical decision limits, record what they are based on and communicate them to users. They may come from an in-house study, the literature or the manufacturer, but their choice must be justified for the population served.

When the laboratory changes an examination or pre-examination procedure, it reviews the associated intervals and limits. If they are no longer appropriate, it communicates the change to users.

Clinical decision limits, such as the thresholds in a clinical practice guideline, are not the same as reference intervals: they indicate when to act, not what is usual in healthy people. The standard asks for both to be documented.

Read it in context: Process requirements, in the ISO 15189 Academy

Structure

Fields the template should include

Measurand, unit and method
Reference interval by age, sex or other partition
Clinical decision limits and the guideline they come from
Source: in-house study, literature, manufacturer
Reference population and selection criteria
Verification of transferability with local samples
Effective date and communication to users
Review and reason

Example

Example: glycated haemoglobin and potassium

Company, people and figures are fictitious: the example only shows what a properly completed record looks like.

Field	Content
HbA1c	Clinical decision limit: 6.5% for the diagnosis of diabetes, according to the clinical guideline adopted by the centre
Serum potassium	Adult reference interval: 3.5-5.1 mmol/L, taken from the manufacturer
Transferability	20 healthy local donors: 19 within the interval · transference accepted
Communication	Published in the test catalogue and on the report · notice to primary care on 20 February 2026
Review	On changing analyser in February 2026: no changes

At the audit

Mistakes auditors commonly flag

Intervals inherited from an old method and not reviewed after the change.
No record of where the interval comes from.
Adult intervals applied to a paediatric population.
Users are not notified when an interval changes.
Reference intervals confused with decision limits.

In Kimobox

How this record is kept in Kimobox

1The intervals for each measurand are kept as a controlled document, with versions and read receipts for staff.
2Clinical reports are generated from a controlled template in the system.
3Each change leaves its trace in the document history.

Frequently asked questions

What people ask us before getting started

Is an in-house study needed for every interval?

No. The standard allows intervals from the literature or the manufacturer provided their application to the population served is justified. A transference verification with a small number of healthy individuals is very widespread practice.

What is a clinical decision limit?

A value above or below which a diagnostic or therapeutic decision is taken, usually set by a clinical guideline or by consensus with clinicians. Unlike the reference interval, it does not describe the healthy population.

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