Collective Opinion Paper on a 2013 AACB Workshop of Experts seeking Harmonisation of Approaches to Setting a Laboratory Quality Control Policy.

Two Quality Control (QC) workshops were conducted in 2013 and 2014 as satellite meetings associated with the Annual Scientific Conference of the Australasian Association of Clinical Biochemists. The purpose of these Workshops was to harmonise the approaches laboratories were taking to developing and implementing a laboratory QC policy. This document represents the collective views from those workshops and is intended to produce guidelines that would be useful as a starting point to harmonise laboratory QC policies under a common framework. One further implication of a harmonised approach to QC policies could be better identification and control of assays with intermediate imprecision and a reduction in the measurement uncertainty of those assays. The key areas of these policies are as follows: Setting of quality standards Selection of materials Selection of concentrations Setting (and re-setting) of QC targets Setting (and re-setting) of QC limits Selection of rules Frequency of running QC Response to out of range results Other supporting QC activities (e.g. Average of Normals) 1. Setting of Quality Standards The goal of the QC process is ensure the quality of patient results, by minimising the risk of issuing erroneous results that may lead to patient harm. The quality limits are set for each analyte to achieve this goal. Without selecting performance goals, it is impossible to determine the critical shift (measured in standard deviations (SD)) that the QC algorithm must detect and hence ensure that the selected QC algorithm is appropriate. Performance goals should be set based on the analyte and the clinical situation where it is used, and should be based on evidence.6–8 It is suggested that an integrated approach is used to set a target imprecision, based on a comparison of the laboratories that achieved analytical imprecision, optimal imprecision (a standard fraction of allowable performance), achievable imprecision (based on the instrument manufacturers’ assay precision specifications) and the percentage of RCPA QAP3 laboratories that achieved optimal imprecision i.e. The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPA QAP) 20th and 50th percentile coefficients of variation (CVs). Performance goals are used to: Guide the setting of target imprecision (where easily achievable) Determine how well specific performance goals are being met Clarify responsibility for improving incapable tests. Guide selection of ‘agreed’ analyte imprecision for target SD Determine the significance of a QC failure e.g. release of patient results. Traditionally, reliability was improved by using an error budget where the two components of error lie within the allowable limit of performance; normal imprecision, plus the size of a critical error detected by a QC algorithm with high probability. By using such a technique, essentially, when a QC run fails, patient results are still reportable. The statistical basis of the performance goal is that it is calculated to have a 90% chance of detecting an error that would cause 5% or more of reported patient results to be outside the allowable limit of performance. Definitions