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CAPA Guidance:

A Corrective and Preventative Action (CAPA) form MUST be completed by all participants not meeting the satisfactory performance criteria for a scheme.  The form needs to be completed within 20 days and submitted in the Participant’s Portal with a summary of the investigation into the reasons for their unacceptable performance together with any corrective actions. Further guidance on completing the form is available below:

Following receipt of an Unsatisfactory Performance notification, a CAPA should be completed via the Participant’s Portal. However, as the system may log you out if you do not submit the form within a set timeframe you may wish to download and enter your data into this CAPA Form template and transfer the information into the CAPA form on the Participant’s Portal.

Root Cause Analysis of Non-satisfactory External Quality Assessments Results

Root-Cause Analysis (RCA) is a systematic approach used for problem solving and identifying the true cause of an unsatisfactory performance.

RCA has four major steps:

  • Documentation of the non-conformance
  • Investigation
  • Root Cause Identification/Analysis
  • Follow-up

Useful information on how to complete a CAPA form can be found below.


Description and documentation of a non-satisfactory result is a key step before initiating investigation and performing root-cause analysis.

Once identified the non-conformance should be immediately objectively and factually described and comprise:


  • The identification of the sample involved
  • The non-conforming measurand
  • The name, version, batch number of the assay and/or reagents used
  • The serial number of any machines used
  • The name and version number of any computer system used
  • Which staff were involved and at what steps
  • The date and time of the testing


What immediate action has been taken? This could be a corrective action like re-issuing an amended report or an observation regarding processes, recalibration of equipment, re-analysis of results or repeat testing.


A thorough investigation needs to be performed. This might include:

A review of all documentation


  • Prints/logs/records/verifications of the assays/instruments used
  • Prints/logs/records/verifications of the results obtained on the same run and/or day
  • Prints/logs/records/verifications of the results obtained with the same batch of reagents on the same instrument
  • Prints/logs/records/verifications of the results of internal and external quality controls
  • Worklists


Following data collection, investigation and preliminary verifications casual factors much be identified.

Proper investigation of causative factors should be done in a multidisciplinary team and involve a quality manager where possible

There are various methods to assist root cause analysis such as: Brainstorming, The 5 Whys, Cause/Effect Diagrams, Flowcharting, Fish-Bone Diagrams, etc.

The choice of thinking methods usually depends on the type and complexity of non-conformity and its associated risks.

Table 1: Possible Causative Factors

Process Examples of Possible Causative Factors
Pre-analytical Testing
  • Non-appropriate handling of the sample e.g. storage, sample mix-up, incomplete sample mixing, sample incorrectly transferred, contamination
  • Mislabelling of secondary tubes
  • Samples not adequately placed in run/plate, etc.
Analytical Testing
  • Malfunction of instrument
  • Incorrect incubation time
  • Contamination/carry over, etc.
Post-analytical Phase
  • Analysis algorithm incorrectly applied
  • Failure in transmission of results
  • Misinterpretation of raw results
  • Transcription error
  • Incorrect unit measurement
Management of material and equipment
  • Reagents expired or release without appropriate validation
  • Storage conditions not met
  • Instrument/equipment not validated or maintained sufficiently
  • Assay or analysis software not validated appropriately
  • Assay failure
Human resources
  • Staff not trained or competent
  • Staff not following procedures
Procurement supplier selection
  • Assay does not meet user requirement specifications e.g. sensitivity
  • Acceptable limits have not been set or updated
  • Procedure on the testing and reporting EQA samples absent or inadequate
  • Lab processes deviate from manufacturer’s instructions



  • What consequences/risks does this issue pose to patient care?
  • Is it likely to affect patient results?
  • Would it affect the clinical utility of testing or decision making?
  • Is it a critical/non-critical incident?


Following the identification of the root-cause(s), appropriate corrective action must be actioned. Also, preventative actions to stop the problem re-occurring must be implemented. 


The corrective action and preventative action plan (CAPA) must be monitored to judge its effectiveness. If the same non-conformance should re-occur it is recommended that full root cause analysis is repeated and a retrospective evaluation performed.


How has this incident affected your practices? Have any changes been implemented, new processes adopted or audits carried out. How can you learn from and improve your service provision in light of this issue?

Where possible UK NEQAS for H&I will be happy to assist and may be able to provide additional samples to labs who wish to monitor the effectiveness of their CAPA.


Have a question regarding the CAPA process?