Quality control review: implementing a scientifically based quality control system

This review focuses on statistical quality control in the context of a quality management system. It describes the use of a ‘Sigma-metric’ for validating the performance of a new examination procedure, developing a total quality control strategy, selecting a statistical quality control procedure and monitoring ongoing quality on the sigma scale. Acceptable method performance is a prerequisite to the design and implementation of statistical quality control procedures. Statistical quality control can only monitor performance, and when properly designed, alert analysts to the presence of additional errors that occur because of unstable performance. A new statistical quality control planning tool, called ‘Westgard Sigma Rules,’ provides a simple and quick way for selecting control rules and the number of control measurements needed to detect medically important errors. The concept of a quality control plan is described, along with alternative adaptations of a total quality control plan and a risk-based individualized quality control plan. Finally, the ongoing monitoring of analytic performance and test quality are discussed, including determination of measurement uncertainty from statistical quality control data collected under intermediate precision conditions and bias determined from proficiency testing/external quality assessment surveys. A new graphical tool, called the Sigma Quality Assessment Chart, is recommended for demonstrating the quality of current examination procedures on the sigma scale.

[1]  R. Jansen,et al.  Can current analytical quality performance of UK clinical laboratories support evidence-based guidelines for diabetes and ischaemic heart disease? – A pilot study and a proposal , 2013, Clinical chemistry and laboratory medicine.

[2]  James O Westgard,et al.  Managing quality vs. measuring uncertainty in the medical laboratory , 2010, Clinical chemistry and laboratory medicine.

[3]  S. Westgard.  Prioritizing risk analysis quality control plans based on Sigma-metrics. , 2013, Clinics in laboratory medicine.

[4]  E. Lenters-Westra,et al.  Three of 7 hemoglobin A1c point-of-care instruments do not meet generally accepted analytical performance criteria. , 2014, Clinical chemistry.

[5]  James O Westgard,et al.  Statistical quality control procedures. , 2013, Clinics in laboratory medicine.

[6]  J O Westgard,et al.  Design and assessment of average of normals (AON) patient data algorithms to maximize run lengths for automatic process control. , 1996, Clinical chemistry.

[7]  Cas Weykamp,et al.  Investigation of 2 models to set and evaluate quality targets for hb a1c: biological variation and sigma-metrics. , 2015, Clinical chemistry.

[8]  John Yundt-Pacheco,et al.  Utilization of assay performance characteristics to estimate hemoglobin A1c result reliability. , 2014, Clinical chemistry.

[9]  Henricus J. Vermeer,et al.  Practical application of Sigma Metrics QC procedures in clinical chemistry , 2011, Clinical chemistry and laboratory medicine.

[10]  K. Sikaris.  Performance criteria of the post-analytical phase , 2015, Clinical chemistry and laboratory medicine.

[11]  W Greg Miller,et al.  Commutability limitations influence quality control results with different reagent lots. , 2011, Clinical chemistry.

[12]  John Yundt-Pacheco,et al.  Validating the performance of QC procedures. , 2013, Clinics in laboratory medicine.

[13]  Sverre Sandberg,et al.  Proposal for the modification of the conventional model for establishing performance specifications , 2015, Clinical chemistry and laboratory medicine.

[14]  James O Westgard,et al.  Internal quality control: planning and implementation strategies , 2003, Annals of clinical biochemistry.

[15]  C G Fraser,et al.  Quality goals in external quality assessment are best based on biology. , 1993, Scandinavian journal of clinical and laboratory investigation. Supplementum.

[16]  Mladen Boršić,et al.  Expression of uncertainty in measurement , 2018, Chemistry International.

[17]  Alexander Katayev,et al.  Changing the paradigm of laboratory quality control through implementation of real-time test results monitoring: For patients by patients. , 2015, Clinical Biochemistry.

[18]  A. Glasper,et al.  Improving the safety of patients in England. , 2013, British journal of nursing.

[19]  David M Bunk,et al.  Roadmap for harmonization of clinical laboratory measurement procedures. , 2011, Clinical chemistry.

[20]  S. Sandberg,et al.  Biological variation – reliable data is essential , 2015, Clinical chemistry and laboratory medicine.

[21]  Anders Kallner,et al.  STRATEGIES TO SET GLOBAL ANALYTICAL QUALITY SPECIFICATION, IN LABORATORY MEDICINE , 1999 .

[22]  Wytze P Oosterhuis,et al.  Gross overestimation of total allowable error based on biological variation. , 2011, Clinical chemistry.

[23]  Linda M. Thienpont,et al.  Metrological traceability of calibration in the estimation and use of common medical decision-making criteria , 2004, Clinical chemistry and laboratory medicine.

[24]  Danielle B Freedman,et al.  Internal quality control: best practice , 2013, Journal of Clinical Pathology.

[25]  Mario Plebani,et al.  Performance criteria and quality indicators for the pre-analytical phase , 2015, Clinical chemistry and laboratory medicine.

[26]  James O. Westgard,et al.  Assessing quality on the Sigma scale from proficiency testing and external quality assessment surveys , 2015, Clinical chemistry and laboratory medicine.

[27]  Eberhard Wieland.  A practical guide to ISO 15189 in laboratory medicine , 2015 .

[28]  Curtis A Parvin,et al.  Assessing the impact of the frequency of quality control testing on the quality of reported patient results. , 2008, Clinical chemistry.

[29]  D Nevalainen,et al.  Evaluating laboratory performance on quality indicators with the six sigma scale. , 2000, Archives of pathology & laboratory medicine.

[30]  J O Westgard,et al.  Allowable imprecision for laboratory tests based on clinical and analytical test outcome criteria. , 1994, Clinical chemistry.

[31]  G. Lippi,et al.  Biological variation: back to basics , 2015, Clinical chemistry and laboratory medicine.

[32]  Sverre Sandberg,et al.  Defining analytical performance specifications: Consensus Statement from the 1st Strategic Conference of the European Federation of Clinical Chemistry and Laboratory Medicine , 2015, Clinical chemistry and laboratory medicine.

[33]  W. Deming.  The Essential Deming: Leadership Principles from the Father of Quality , 2012 .

[34]  C Ricós,et al.  Current databases on biological variation: pros, cons and progress. , 1999, Scandinavian journal of clinical and laboratory investigation.

[35]  P H Petersen.  Quality specifications based on analysis of effects of performance on clinical decision-making. , 1999, Scandinavian journal of clinical and laboratory investigation.

[36]  G S Cembrowski,et al.  Assessment of "Average of Normals" quality control procedures and guidelines for implementation. , 1984, American journal of clinical pathology.

[37]  M Hørder,et al.  Analytical goals for the acceptance of common reference intervals for laboratories throughout a geographical area. , 1988, Scandinavian journal of clinical and laboratory investigation.

[38]  Mario Plebani,et al.  The CCLM contribution to improvements in quality and patient safety , 2012, Clinical chemistry and laboratory medicine.

[39]  M. Serteser,et al.  A new approach to calculating the Sigma Metric in clinical laboratories , 2015, Accreditation and Quality Assurance.

[40]  Ferruccio Ceriotti,et al.  How to define a significant deviation from the expected internal quality control result , 2015, Clinical chemistry and laboratory medicine.

[41]  R G HOFFMANN,et al.  THE "AVERAGE OF NORMALS" METHOD OF QUALITY CONTROL. , 1965, American journal of clinical pathology.

[42]  Sten A Westgard,et al.  The quality of laboratory testing today: an assessment of sigma metrics for analytic quality using performance data from proficiency testing surveys and the CLIA criteria for acceptable performance. , 2006, American journal of clinical pathology.