Guest Essay

Part three of an ongoing series on Internal Quality Control (IQC) by Dietmar Stockl. Dr. Stockl looks again at QC data examples from the real world of the laboratory, this time looking at the case when a laboratory purposes uses the wrong standard deviation.

Dietmar Stockl, colleague, friend, and expert in statistics, starts a series on looking at QC data examples from the real world of the laboratory. Sometimes what happens in reality is different than what's predicted in theory.

Part three of an ongoing series on Internal Quality Control (IQC) by Dietmar Stockl. Dr. Stockl looks again at QC data examples from the real world of the laboratory.

Despite years of intensive use and the recent advent of “high sensitivity” assays, fundamental questions about cardiac Troponin methods remain. Is precision of 10% CV required at the upper 99th percentile value of the reference population? Are methods with CV > 20% unacceptable? Is a change of 20% in an individual significant? Callum G Fraser, the internationally respected expert on biological variation, provides a logical technique for the interpretation of serial test results.