ISO 15189:2022 · Section 7 · Process requirements
Clause 7.3.7: Ensuring validity of examination results
Check the exact requirement in your licensed copy of the standard.
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What this clause is about
Confidence in examination results requires more than a successful calibration or an occasional satisfactory comparison. The laboratory needs a coordinated system for detecting unacceptable performance, preventing unreliable release, and investigating possible effects on patients. Internal quality control, external quality assessment or proficiency testing, and comparability checks provide different information and should be interpreted together rather than treated as interchangeable obligations.
Design internal quality control around examination risk, method stability, clinical decision points, and the opportunity to detect error before results are released. Choose suitable materials, concentrations, frequency, and acceptance rules with documented reasoning. Staff need clear instructions for reviewing patterns, responding to rejection, and withholding affected results. Repeating a control until it passes does not explain the original failure or establish that patient results are reliable.
Use suitable EQA or PT where available and process materials in a way that reflects routine practice within scheme instructions. Review every outcome, including comments, trends, and apparently satisfactory results that reveal emerging differences. When an appropriate scheme is unavailable, establish and document a justified alternative for external performance assessment. Investigate unacceptable outcomes for technical and clinical significance rather than filing the provider report alone.
Where results come from different instruments, sites, or methods used within the service, assess comparability across relevant intervals and decision points. Investigations should identify affected work, possible patient impact, corrective action, and evidence of effectiveness. LabToolkit Pro can support QC charts, review forms, and action records, while competent staff remain responsible for interpreting signals and authorizing resumed reporting.
What assessors typically ask to see
- How do control materials, concentrations, frequency, and rejection rules address examination risk and important clinical decision points?
- What prevents release of affected patient results when controls fail, trends emerge, or control information is unavailable?
- How are EQA or PT materials handled within scheme instructions while avoiding special treatment that hides routine performance?
- What alternatives are used when suitable external schemes are unavailable, and how is their adequacy justified and reviewed?
- How is comparability demonstrated between instruments, sites, or methods that may contribute results to the same patient's care?
- How do investigations define the affected time period, assess patient impact, authorize resumption, and confirm that corrective actions worked?
Documents and records that usually provide evidence
- IQC plan explaining material selection, concentration coverage, frequency, acceptance rules, review responsibilities, and response to unacceptable performance.
- Control charts and review records showing observations, patterns, rejected runs, troubleshooting decisions, and authorized return to patient reporting.
- EQA or PT participation records with submitted results, provider feedback, local interpretation, investigation, and action where performance is concerning.
- Alternative external assessment plans documenting the reason a scheme is unsuitable or unavailable and the evidence supporting the chosen approach.
- Comparability studies identifying systems, sites, concentration coverage, clinical requirements, observed differences, acceptance decisions, and necessary reporting qualifications.
- Patient impact assessments and corrective action records linking quality failures to affected results, user communication, effectiveness checks, and closure.
Ready-made forms mapped to clause 7.3.7: IQC Frequency Determination Form, In-house IQC Preparation Log, IQC Statistical Tool — Levey-jennings Chart Setup, IQC Daily Log, CV Calculator — Alternative IQC Method, Levey-Jennings chart & Westgard multirule monitor, Sigma metric & QC strategy planner, EQA Dashboard Tracker, 5-year EQA Programme Plan, EQA Report Review Checklist, EQA / proficiency-testing result evaluation.
Common findings to avoid
- Control values are accepted automatically without reviewing sustained shifts or trends that may indicate a developing examination problem.
- A failed control is repeatedly rerun until acceptable, but no cause, affected period, or patient impact is assessed.
- EQA reports are filed as satisfactory without reviewing relevant bias patterns, provider comments, or differences at decision points.
- Comparability checks omit a backup instrument that is used for patient testing whenever the primary system is unavailable.
How LabToolkit Pro maps documents to this clause
Each SOP, form and record in LabToolkit Pro can carry clause tags. When a document tagged 7.3.7 becomes effective, it counts as direct evidence on the readiness dashboard for ISO 15189:2022; links from other standards through the crosswalk are shown separately as indicative coverage. Gaps appear clause by clause, so you can see which parts of 7.3.7 still need a controlled document or a current record. Readiness is a planning aid — only an accreditation body confirms conformity.
Frequently asked questions
Does satisfactory EQA replace internal quality control?
No. External assessment provides periodic information about performance relative to an external basis, while internal control supports ongoing detection of problems during routine work. Their limitations differ. A satisfactory external result cannot establish that every intervening patient run was acceptable, and stable internal controls may not reveal all systematic differences.
What if no suitable EQA or PT scheme exists?
Document the search and the reasons available schemes do not meet the examination need. Select an alternative that provides meaningful external evidence, such as an appropriate interlaboratory comparison or suitable reference material. Define responsibilities, acceptance criteria, review arrangements, and limitations, then reassess availability and suitability periodically.
When should comparability be checked?
Use a planned approach that reflects how systems are used and the consequences of differences. Include relevant concentrations and decision points, and reassess after changes likely to affect agreement. If results are not acceptably comparable, investigate and control the difference through technical action, reporting qualifications, or restrictions appropriate to patient care.
Check the exact requirement in your licensed copy of the standard.
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