FLOWCHART FOR HANDLING DEVIATING EQA-RESULT
Gunn B B Kristensen, Kristine Solem and Pål Rustad
NKK, Norsk Klinisk-kjemisk Kvalitetssikring
e-mail:[email protected]
Is there any explanation in the comment
External cause1
letter?
Yes
NO
NO
Internal cause2
Do the acceptance
limits indicate a considerable deviation?
Yes
Yes
Internal/external
cause3
Is the deviation in accordance with previous EQA results?
NO
NO
Internal cause4
Were the results for internal quality control
(IQC) OK in the period the analysis was performed?
Yes
Internal cause5
NO
Were the reagents and calibration status OK?
Yes
Yes
Has the manufacturer changed the recommendation regarding
reagents, calibrator or the given value of the calibrator recently?
Internal/external
cause6
NO
Is the assigned
value (AV) traceable to a reference method?
NO
Yes
External
cause8
Is the deviation representative for your method?
Yes
External
cause7
Yes
NO
Is the deviation representative for your
method?
NO
External
cause9
Is AV calculated from original results?
Yes
NO
NO
External
cause10
Is AV calculated on sufficient number of results (<4)?
NO
Yes
NO
Internal cause11
Was the instruction from the
EQA organizer followed?
Yes
NO
External cause12
Has the EQA organizer registered the correct method and result?
NO
Internal cause13
Yes
Has the laboratory registered the correct method and result?
Yes
NO
External cause14
Have the samples been sent in a proper way?
Yes
Internal cause
NO
15
Is the analysis performed in the way the manufacturer prescribe?
Yes
Yes
Is the variation in the EQA results for your method large?
NO
Internal/external
cause17
If several samples are measured – is the deviation systematic for all?
NO
Internal cause18
Yes
Does repeated analysis of stored material also give a deviation?
Yes
Internal/external
cause19
External cause16
NO
NO
Does re-analysis of new material sent from the EQA organizer also give a deviation?
NO
External cause20
Yes
Is the instruction letter correct?
Yes
UNKNOWN
CAUSE21
The flowchart consists of several questions indicating possible causes for the deviating result, further
explained in the comments corresponding to the footnote numbers, see attachment