Course Content

12 - Understanding Interlab Comparison



Laboratories using the same measurement procedure and analyzing the same control material will generate similar means and SDs.  This information is a valuable source to determine the target value of the QC material for a laboratory and compare their method’s performance to their peers.

In this activity, participants are introduced to coefficient of variation index (CVI).  Based on the information supplied from the inter-laboratory comparison report, participants will investigate a QC problem.

Key Message

  • Inter-laboratory peer comparisons can help identify method and PT problems.
  • The peer mean is an excellent source of the true (target) value for each control.
  • Coefficient of Variation Index is a peer-based metric of imprecision.

Self Assessment

Can you: 

  • Calculate the SDI and CVI?
  • Verify the 4 key numbers used to monitor and evaluate performance?
  • Perform an investigational analysis regarding a summary statistic flag?