Monitoring EQA Performance : Investigating the source of the problem In order to identify the source of the problem it is useful to be aware of the most common causes of poor EQA performance. Errors can occur at any stage of the testing process however EQA is most concerned with detecting analytical errors i.e. errors that occur during the analysis of the sample. Most analytical errors can be easily divided into three main areas; clerical errors, systematic errors and random errors. Systematic errors result in inaccurate results that consistently show a positive or negative bias. Random errors on the other hand affect precision and result in fluctuations in either direction. The flowchart (below) is designed to help you investigate any apparent poor performance. Is the parameter result within acceptable limits of performance? YES • Target Score >50 • SDI <2SDPA • % Deviation < acceptable limits of performance Send corrected result to RIQAS along with relevant documentation to support the case. Verify instrument, method and units are registered correctly for each parameter. Especially important for initial submission and when registration changes have been made. Review the summary page. Are the majority of results flagged? Advise RIQAS of correct details Review Levey-Jennings charts. Are any points outside +/- 1SD? Review instrument parameters and calibration. Has the reagent batch been changed? Review IQC results from the time the EQA sample was tested. Look for trends within the data • Positive/Negative bias • Poor precision • Changes in performance due to change in reagent, calibrator or standardisation There may be a problem specific to that sample • Incorrect sample tested • Reconstitution error • Sample storage Look for shifts or trends Investigate and take corrective action The largest global EQA scheme QUALITY CONTROL Information correct at time of print. Randox Laboratories Ltd is a subsidiary of Randox Holdings Limited a company registered within Northern Ireland with company number N.I. 614690. VAT Registered Number: GB 151 6827 08. Product availability may vary from country to country. Please contact your local Randox representative for information. Products may be for Research Use Only and not for use in diagnostic procedures in the USA. Review performance over the cycle Verify that the reported result and units reflect what was obtained. Has a transcription