Quality in Laboratory Hemostasis and Thrombosis E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 775

Veröffentlichungsjahr: 2013

Beschreibung

Quality in Laboratory Hemostasis and Thrombosis Second Edition Edited by Steve Kitchen, Clinical Scientist, Sheffield Haemophilia and Thrombosis Centre, Royal Hallamshire Hospital and Scientific Director, UK National External Quality Assessment Scheme (FQAS) for Blood Coagulation, Scientific Director, WHO and WFH International External Quality Assessment Programs for Blood Coagulation, Sheffield, UK John D Olson, Professor and Vice Chair for Clinical Affairs, Department of Pathology, University of Texas Health Sciences Centre, San Antonio, Texas, USA F. Eric Preston, Emeritus Professsor of Haematology, University of Sheffield and Director, WHO and WFH International External Quality Assessment Programs for Blood Coagulations, Sheffield, UK The hemostasis laboratory has a vital role in the diagnosis and management of patients with familial and acquired hemorrhagic and thrombotic disorders. Rapid changes in the number and complexity of tests in this discipline have presented challenges for laboratories, as they develop quality programs for the oversight of this testing. Quality in Laboratory Hemostasis and Thrombosis has been completely revised and updated to reflect the changing process of managing quality. The second edition provides information on all aspects of testing, from pre-analytic to analytic and result reporting, in addition to external quality assurance. Chapters throughout the book include the development of global guidelines for methods, as well as the preparation of international standard plasmas and reagents. Designed to capture the elements of quality at all levels of the practice of laboratory hemostasis and thrombosis, this book will guide the reader through the development of a quality program to support all activities in the hemostasis laboratory, both simple and complex. Titles of related interest Lee: Textbook of Hemophilia, 2e (2010) ISBN 9781405169141 Federici: Von Willebrand Disease: Basic and Clinical Aspects, 1e (2011) ISBN 9781405195126 Ma: Hemophilia and Hemostasis: A Case Based Approach to Management, 2e (2012) ISBN 9780470659762

Leseprobe

Contents

Cover

Title Page

Copyright

Contributors

Foreword

Preface

Part 1: General Quality Program

Chapter 1: General quality planning in the hemostasis laboratory

Introduction

The principles

The tools

The application of the tools in the laboratory

Summary

References

Chapter 2: Hemostasis test validation, performance, and reference intervals: international recommendations and guidelines

Hemostatic test validation concepts

Continued performance of coagulation/hemostasis assays

Reference interval

Appendix: Standards and guideline developing organizations

Statistics

Acknowledgments

References

Chapter 3: Causes of errors in medical laboratories

Overview on medical errors

Diagnostic errors: the laboratory scenario

Preanalytical errors

Analytical errors

Postanalytical errors

Conclusion

References

Chapter 4: International standards in hemostasis

Introduction

International standards and international units

Heparin and LMW heparin

Thromboplastins

Coagulation factors and inhibitors

Fibrinolysis standards

References

Chapter 5: Sample integrity and preanalytical variables

Introduction

Conclusion

References

Chapter 6: Internal quality control in the hemostasis laboratory

Introduction

Frequency of IQC testing

Acceptable limits for IQC

Storage and processing of IQC results

Accreditation and regulatory bodies

Conclusion

References

Chapter 7: External quality assessment in hemostasis: its importance and significance

Overview

Target values

The evaluation of laboratory performance

Monitoring results: the role of the laboratory

The educational role of EQA

Additional advantages of EQA programs

Recent developments

Establishing EQA programs in developing countries

References

Chapter 8: The unique challenges of hemostatic testing in children

Introduction

Normal hemostasis

Developmental hemostasis

Pediatric reference ranges: challenges and deviations

Local pediatric reference range development

The effect of the assay method

Test sampling

Global hemostasis parameters

Thrombophilia testing

When is thrombophilia testing indicated in children

Monitoring currently administered anticoagulants

Unfractionated heparin

Low molecular weight heparin

Vitamin K antagonists

POC INR monitoring

New anticoagulants in children

Conclusion

References

Part 2: Quality in Coagulation Testing

Chapter 9: Initial evaluation of hemostasis: reagent and method selection

Introduction

Instrument selection

Evaluation of the method

References

Chapter 10: Assay of factor VIII and other clotting factors

Pretest variables

One-stage assay of factor VIII:C or factor IX:C

Assays in the presence of strong lupus anticoagulant

One-stage assay components

Factor assays in the presence of severe deficiency

Assay of elevated factor VIII:C

Two-stage clotting assay for FVIII:C

Chromogenic assay for factor VIII:C in plasma

Factor VIII:C and FIX:C assays following clotting factor infusions

References

Chapter 11: Application of molecular genetics to the investigation of inherited bleeding disorders

Hemophilia A and B

The genes and their mutations

Other rare bleeding disorders

Internal quality control

References

Chapter 12: Detecting and quantifying acquired functional inhibitors in hemostasis

Introduction

Clinical manifestations of hemostasis inhibitors

Screening tests for inhibitor detection

Differential classification of inhibitors

Assay of inhibitors against individual coagulation factors

Assay characteristics

Pitfalls and limitations of the inhibitor assay

Conclusion

References

Chapter 13: Standardization of d-dimer testing

Introduction

Heterogeneity of D-dimer containing fragments

Specificity of monoclonal antibodies directed to D-dimer motif

Calibrators for D-dimer assays

Standardization of D-dimer assays

Harmonization of D-dimer assays

Problems in daily practice

Reference material for D-dimer assays

Conclusion

References

Chapter 14: Point-of-care testing in hemostasis

Introduction

aPTT testing

aCT

Thrombin time

Low molecular weight heparin monitoring

D-dimer

Thrombelastography

Management of POCT services

Conclusion

References

Part 3: Quality in Testing for Platelet Function and von Willebrand Disease

Chapter 15: Diagnostic assessment of platelet function

Bleeding time

Prothrombin consumption

Platelet counting and morphology

The platelet function analyzer

The VerifyNow and point-of-care tests

Platelet aggregometry

Platelet secretion

Flow cytometry

Clot retraction

Signaling pathways

In vitro studies on thrombus formation

Platelet procoagulant activity

New technologies

References

Chapter 16: Laboratory evaluation of heparin-induced thrombocytopenia

HIT syndrome

Key concepts in HIT

Platelet activation assays

Platelet aggregation assays

PF4-dependent enzyme-immunoassays

PF4-dependent particle-based immunoassays (rapid assays)

Fluid-phase immunoassays

Approach of the McMaster platelet immunology laboratory

References

Chapter 17: Laboratory evaluation of von Willebrand disease: phenotypic analysis

Introduction and background

Phenotypic assays used in the diagnosis of vWD

A diagnostic laboratory process for vWD

Recommendations and conclusions

Acknowledgments

References

Chapter 18: Laboratory analysis of von Willebrand disease: molecular analysis

Introduction

Type 3 VWD

Type 2 VWD

Type 1 VWD

Mutation analysis

Prenatal diagnosis

Internal quality control

External quality control

External quality assessment

Reporting

References

Part 4: Quality in Thrombophilia Testing and Monitoring Anticoagulation

Chapter 19: Quality issues in heritable thrombophilia testing

Introduction

The thrombophilia screen: what to include?

Which methods?

What samples and when?

Interpreting the results

Who should be tested?

References

Chapter 20: Evaluation of antiphospholipid antibodies

Antiphospholipid syndrome

Antiphospholipid antibodies

Lupus anticoagulants

Lupus anticoagulant assays

Lupus anticoagulant assay performance

Assay of lupus anticoagulant in subjects treated with coumarin

Anticardiolipin assays

Anticardiolipin assay performance

Anti-beta2 glycoprotein I antibody assays

Anti-beta2 glycoprotein I antibody assay performance

Summary and conclusion

References

Chapter 21: Monitoring heparin therapy

Heparin

Limitations of heparin

Low molecular weight heparins

Current techniques used to measure heparin in plasma

IIa inhibition assays

Quality control and assurance

Heparin calibration curves

Results from quality assurance programs

Summary

Monitoring LMWH

References

Chapter 22: Monitoring oral anticoagulant therapy with vitamin K antagonists

Introduction

Thromboplastin calibration

Conversion of PT into INR and issues affecting results

Limits of the INR

Implementation of the INR

Conclusions and future directions

References

Chapter 23: Monitoring new anticoagulants

Introduction

New anticoagulants

Calibration for accuracy of measurement

Methods for monitoring indirect FXa inhibitors

Methods for monitoring direct Xa inhibitors

Methods for monitoring DTIs

Methods for monitoring dual inhibitor of FXa and thrombin

Monitoring anticoagulants using global screening tests

Summary

References

Index

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Library of Congress Cataloging-in-Publication Data

Quality in laboratory hemostasis and thrombosis / edited by Steve Kitchen, John D. Olson, F. Eric Preston ; foreword by Frits R. Rosendaal. – 2nd ed. p. ; cm. Includes bibliographical references and index. ISBN 978-0-470-67119-1 (hardback : alk. paper) I. Kitchen, Steve, Dr. II. Olson, John David, 1944- III. Preston, F. E. [DNLM: 1. Hemostatic Techniques. 2. Anticoagulants. 3. Blood Coagulation Disorders, Inherited–diagnosis. 4. Blood Coagulation Factors. 5. Clinical Laboratory Techniques. 6. Thrombophilia–diagnosis. WH 310] 616.1′57075–dc23 2012044510

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Cover image: Internal. Top: courtesy of Bert Verbuggen; bottom: courtesy of Wayne Chandler. Cover design by Andrew Magee Design Ltd

Contributors

Trevor W. Barrowcliffe MA, PhD Formerly National Institute for Biological Standards and Control (NIBSC) Potters Bar, Hertfordshire, UK

Mary E. Bauman RN, MN, NP Stollery Childen’s Hospital University of Alberta Edmonton, AB, Canada

Anthony K.C. Chan MBBS, FRCPC, FRCPath McMaster Children’s Hospital/Hamilton Health Sciences Foundation Chair in Pediatric Thrombosis and Hemostasis Department of Pediatrics, McMaster University Hamilton, ON, Canada

Vanessa Chan BSc, MLT Department of Paediatric Laboratory Medicine The Hospital for Sick Children Toronto, ON, Canada

Wayne L. Chandler MD Coagulation Laboratory Department of Pathology and Genomic Medicine The Methodist Hospital Physician Organization Houston, TX, USA

Myriam Dardikh MSc Department of Laboratory Medicine Laboratory of Haematology Radboud University Nijmegen Medical Centre Nijmegen, The Netherlands

Philippe de Moerloose MD Haemostasis Unit Department of Internal Medicine University Hospital and Faculty of Medicine Geneva, Switzerland

Morten Dunø MD, PhD Department of Clinical Genetics Copenhagen University Hospital (Rigshospitalet) Copenhagen, Denmark

Emmanuel J. Favaloro PhD, FFSc (RCPA) Department of Hematology ICPMR, Westmead Hospital Westmead, NSW, Australia

Dorothy (Adcock) Funk MD Colorado Coagulation a business unit of Esoterix, Inc., Englewood, CO, USA

Chris Gardiner PhD Haematology Department University College London Hospitals NHS Trust; and Nuffield Department of Obstetrics and Gynaecology John Radcliffe Hospital Oxford, UK

Anne C. Goodeve PhD Sheffield Haemostasis Research Group Department of Cardiovascular Science University of Sheffield Sheffield; and Sheffield Diagnostic Genetics Service Sheffield Children’s NHS Foundation Trust Sheffield, UK

Elaine Gray PhD National Institute for Biological Standards and Control Potters Bar, Hertfordshire, UK

Michael Greaves MD FRCP FRCPath Aberdeen Royal Infirmary Head of College of Life Sciences and Medicine, University of Aberdeen, Scotland, UK

Anthony R. Hubbard PhD National Institute for Biological Standards and Control Hertfordshire, UK

Martine Jandrot-Perrus MD, PhD INSERM U698 and Paris 7 University Paris, France

Ian Jennings PhD UK NEQAS for Blood Coagulation Sheffield, UK

Marilyn Johnston MLT, ART Hemostasis Reference Laboratory Hamilton, ON, Canada

Dianne Kitchen FIBMS UK NEQAS Blood Coagulation Sheffield, UK

Steve Kitchen PhD Sheffield Hemophilia and Thrombosis Centre Royal Hallamshire Hospital Sheffield; and UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation WHO and WFH International External Quality Assessment Programs for Blood Coagulation Sheffield, UK

Britta Laros-van Gorkom MD, PhD Department of Haematology Radboud University Nijmegen Medical Centre Nijmegen, The Netherlands

Stefan Lethagen MD, PhD Copenhagen University Copenhagen; and Medical and Science Haemophilia R&D Novo Nordisk A/S, Denmark

Giuseppe Lippi MD Clinical Chemistry and Haematology Laboratory Department of Pathology and Laboratory Medicine Academic Hospital of Parma Parma, Italy

Samuel Machin MB ChB, FRCP, FRCPath Haematology Department University College London Hospitals NHS Trust; and Haemostasis Research Unit, Haematology Department University College London London, UK

Ian Mackie PhD, FRCPath Haematology Department University College London Hospitals NHS Trust Haemostasis Research Unit Haematology Department University College London London, UK

Richard A. Marlar PhD Pathology and Laboratory Medicine Oklahoma City VA Medical Center; and Department of Pathology University of Oklahoma Health Sciences Center Oklahoma City, OK, USA

M. Patricia Massicotte MD, MHSc Stollery Childen’s Hospital University of Alberta Edmonton, AB, Canada

Jane C. Moore ART, BSc Departments of Pathology and Molecular Medicine, and Medicine Michael G. DeGroote School of Medicine, McMaster University Hamilton Regional Laboratory Medicine Program Hamilton, ON, Canada

Lars Bo Nielsen MD, PhD Department of Clinical Biochemistry Rigshospitalet and Department of Biomedical Sciences; and University of Copenhagen Copenhagen University Hospital (Rigshospitalet) Copenhagen, Denmark

Alan Nurden PhD Centre de Référence des Pathologies Plaquettaires Plateforme Technologique d’Innovation Biomédicale Hôpital Xavier Arnozan Pessac, France

Paquita Nurden MD, PhD Centre de Référence des Pathologies Plaquettaires Plateforme Technologique d’Innovation Biomédicale Hôpital Xavier Arnozan Pessac, France

John D. Olson MD, PhD Department of Pathology University of Texas Health Science Center San Antonio, TX, USA

Ian R. Peake PhD Sheffield Haemostasis Research Group Department of Cardiovascular Science University of Sheffield Sheffield, UK

F. Eric Preston MD, FRCPath, FRCP University of Sheffield Sheffield; and WHO and WFH International External Quality Assessment Programs for Blood Coagulation Sheffield, UK

Guido Reber PhD Haemostasis Unit Department of Internal Medicine University Hospital and Faculty of Medicine Geneva, Switzerland

Alok Srivastava MD, FRACP, FRCPA, FRCP Department of Hematology Christian Medical School Vellore, India

Armando Tripodi PhD Angelo Bianchi Bonomi Hemophilia and Thrombosis Center Department of Internal Medicine University School of Medicine and IRCCS Cà Granda Maggiore Hospital Foundation Milan, Italy

Bert Verbruggen PhD Laboratory of Clinical Chemistry and Haematology Jeroen Bosch Hospital’s-Hertogenbosch, The Netherlands

Isobel D. Walker MD MPhil (Medical Law), FRCPath University of Glasgow, Glasgow; and NEQAS for Blood Coagulation Sheffield, UK

Theodore (Ted) E. Warkentin MD Departments of Pathology and Molecular Medicine, and Medicine Michael G. DeGroote School of Medicine McMaster University Transfusion Medicine Hamilton Regional Laboratory Medicine Program Hamilton, ON, Canada

Foreword

Thou art always figuring diseases in me, but thou art full of error: I am sound

(William Shakespeare. Measure for measure (1604); Act I, Scene II)

A correct diagnosis is the cornerstone of medicine. Without it, no remedy can be prescribed, or prognosis given. Although laboratory tests are only a part of the diagnostic arsenal, together with history taking, clinical examination, and imaging techniques, few diagnoses are arrived at without some form of laboratory test. Inadequate tests may lead to either false reassurance or false alarm. They may lead to the erroneous choice not to give treatment when treatment would be beneficial, or even to prescribe the wrong treatment, which is likely to be harmful. It is therefore of the utmost importance that whenever laboratory tests are performed, the results are reliable.

Laboratory tests in the field of thrombosis and hemostasis are notoriously difficult, which is related to the large variety in techniques that are used, and the sensitivity of many assays to small preanalytical and analytical variation. Therefore, quality assurance is crucial, and no hemostasis laboratory can afford not to invest in internal and external quality control. The book, Quality in Laboratory Hemostasis and Thrombosis, edited and written by authorities in the field, since its first edition in 2008, has become a indispensable help for those who wish to set up a hemostasis laboratory, as well as those who already work in such a place. For, to quote from the first chapter: “Process is never optimized; it can always be improved.”

The book has two parts: the first eight chapters give a scholarly overview of the concepts that underlie quality assurance, explaining the various aspects of test validation, with its components, of which accuracy and precision are the most important: does a test measure what it is supposed to measure, and does it do so with acceptable reproducibility. Subsequent chapters in this first part explain in detail how internal quality control deals with precision and external quality control with accuracy. The development of international standards is an important and ongoing development in improving accuracy and comparability of hemostasis laboratory tests. Here, the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis, working together with the World Health Organization, has played a major role. Over the years we have witnessed the emergence of large external quality assurance programs, in which samples are sometimes sent to more than a thousand participating laboratories. Such programs not only allow laboratories to evaluate their performance, but also to group results by reagent or instrument, which leads to valuable insights, and further quality improvement. Newly added chapters to the second edition deal with the causes of laboratory error, the understanding of which is indispensable in optimizing laboratory performance, and the performance and interpretation of hemostatic tests in children.

In the second part of the book, Chapters 9 through 23, a detailed description is given of all major assays in hemostasis, grouped in a series of chapters on coagulation factor assays, on primary hemostasis (platelets and von Willebrand factor), and on thrombophilia testing and anticoagulant treatment monitoring. These chapters give the reader invaluable information on the performance and interpretation of these tests. A newly added chapter that was much missed in the first edition deals with heparin-induced thrombocytopenia.

The ultimate test for a laboratory test is whether it improves medical care, that is, reduces morbidity and mortality, which depends on the effect a negative or positive test result has on the treatment of a patient. A test that does not affect clinical management is a waste of resources. Both at the beginning and the end of laboratory tests there is usually a clinician, who first makes the decision to order a test, and subsequently has to interpret the test result. Although these clinical decisions and interpretation are not part of the content of this book, which would have made it unwieldy to say the least, these are of obvious importance, and one of the tasks of the individuals working in hemostasis laboratories is to educate clinicians about the clinical value of the various assays. I am quite confident that in the field of hemostasis and thrombosis more useless than useful testing is done, and that in medicine as a whole the greatest waste of money is on redundant diagnostics. The practice of medicine knows a wide variety of tests, which generally serve three purposes, either to diagnose a disease, or to test for a risk factor for disease, or to screen for either of these. This distinction is rarely sharply made, while it seems that clinically one type (diagnosing a disease) is almost always indicated and useful, and another type (testing for risk factors) only rarely is. While it is logical to find out which disease a patient with complaints has, it is not so logical to try and identify the causes of that disease, or even to try and identify those risk factors in nondiseased individuals, such as relatives of individuals with thrombosis. The reason the distinction between diagnosing a disease and identifying a risk factor is not always sharply made, is possibly because in some diseases in the field, notably bleeding disorders, there is an almost one-to-one relationship between the cause of the disease and the disease itself. While excessive bleeding is the disease and the clotting factor level a cause, individuals with no factor VIII or IX will invariably have the clinical disease of hemophilia, and therefore, measuring the clotting factor level has become synonymous to diagnosing hemophilia. This is quite different for thrombosis. Thrombosis (deep vein thrombosis or pulmonary embolism) is a disease, whereas thrombophilia is not. Given the multicausal nature of the etiology of thrombosis, in which multiple risk factors need to be present to lead to disease, it is far from self-evident that testing for thrombophilic abnormalities has any clinical value. So far, there are no clinical studies that show a benefit of such testing, although it is performed on a broad scale. Whenever you order a test or are requested to perform a test, question whether the result could possibly change anything. If not, or if the only benefit is to satisfy the doctor's curiosity, the test should not be done.

The reliability of a particular assay should be viewed in the context in which the test is ordered. Suppose one would order a test for high factor VIII as a prothrombotic risk factor, the above mentioned notwithstanding, an error of five IU/dL would be irrelevant, since the purpose is to discriminate between levels of over 150 or 200 IU/dL versus plasma concentrations around 100 IU/dL. The same error in a factor VIII assay to diagnose hemophilia A could be disastrous.

A clinician, when ordering a test, will have to deal with so-called prior probabilities, which is of particular relevance in screening tests. A slightly prolonged aPTT has a vastly different meaning when found in a healthy woman who had four uneventful deliveries who has come to the hospital for a tubal ligation, than in an 18-month-old boy who needs to undergo a duodenoscopy with possible biopsies. She is unlikely to have a bleeding tendency, even when the aPTT is prolonged, while the young boy may suffer from hemophilia. Screening tests affect the likelihood of disease, which, according to Bayes' theorem, is also a function of the prior probability of disease. Virtually, all tests that use reference ranges based on statistical cutoff values, such as the population mean plus or minus two standard deviations, are screening tests, that do neither establish a risk factor or a disease, but only, when abnormal, affect the likelihood of that state. Nature does not use standard deviations, and using a cutoff of two standard deviations by definition finds 2.5% of the population below, or over, such a cutoff. In reality, diseases and risk factors may have prevalences that exceed, or, more usual, lie far below this figure. Tests using “normal ranges” therefore can never establish an abnormality, and should be followed by more specific tests, such as clotting factor assays or genetic tests.

Over the last decades, major progress has been made in quality assurance of hemostatic laboratory assays. In this new edition of Quality in Laboratory Hemostasis and Thrombosis, all chapters have been updated and several new chapters have been added. This book will remain an indispensable part of every hemostasis laboratory, where, given its hand-on nature, it will rarely sit to get dusty on the shelves.

Frits R. Rosendaal Former Chairman ISTH Council, President XXIV ISTH Congress, Former Chairman Netherlands Society of Thrombosis & Haemostasis, Leiden University Medical Centre, The Netherlands

Preface

In the past two to three decades, few disciplines, if any, in laboratory medicine have seen the growth in the number and complexity of testing as that experienced in the discipline of hemostasis and thrombosis. These rapid changes have presented challenges for laboratories as they develop quality programs for the oversight of this testing. The quality issues extend across all levels of testing and all sizes of laboratories. The field of laboratory medicine continues to evolve and there have been important advances since the first edition of this text was published. We, therefore, accepted the invitation to bring this text up to date in the second edition.

In our original discussions about a title for the first edition, we had an interesting discussion regarding possibilities of “…the Hemostasis and Thrombosis Laboratory” and “…Laboratory Hemostasis and Thrombosis.” The distinction is subtle but relevant, the former being a place and the latter a discipline. Quality issues in this discipline extend well beyond the walls of the laboratory. In this second edition, we have retained contributions from all the original recognized experts which have been updated, and added a few new chapters based on the comments received in the intervening years since the first edition appeared. These experts have provided information on elements of managing quality as it relates to individual tests or groups of tests extending from nuances of internal quality control to the challenges in many areas where standardization may be absent or inadequate. There is information on all aspects of testing from preanalytic to analytic and results reporting as well as external quality assurance. In addition, chapters are included regarding the development of international guidelines for methods as well as the preparation of international standard plasmas and reagents.

Quality is a changing process, continually striving to improve the product while reducing errors and improving safety. This book represents an event in this continuum, and is intended to capture the elements of quality at all levels of the practice of Laboratory Hemostasis and Thrombosis, bringing these up to date since the construction of the first edition during 2008. We believe that it will continue to provide a useful guide for those involved hemostasis and thrombosis testing, whether very simple, like the point of care, or complex, like the major reference laboratory.

Steve KitchenJohn D. OlsonF. Eric Preston

PART 1

General Quality Program

1

General quality planning in the hemostasis laboratory

John D. Olson1,2

1Department of Pathology, University of Texas Health Science Center, San Antonio, TX, USA2University Health System, San Antonio, TX, USA

Introduction

Quality:

Invisible when it is good.

Impossible to ignore when it is bad.

“So,” you might ask, “What is quality, anyway?” The word quality repeatedly infiltrates our discussions and interactions as we work to produce or choose a product. The Oxford English Dictionary devotes more than 3000 words in its effort to define the many variations on the use of this word [1]. We may all have difficulty with a definition, but we do know what we mean. The customer of the product or service defines many aspects of its quality while those who are producing define many others. Stated in its simplest terms, quality is the condition or state of a person, thing, or process.

The principles

As early as the middle of the 1400s, boat makers in Venice, Italy, introduced the principle of “mass production” with the manufacture of boats in the sequential assembly of preproduced parts. This assembly line process was refined in the modern sense by Henry Ford between 1900 and 1910. The scientific elements of quality management systems began in the 1930s with the publication of Shewhart in 1931 [2], providing a scientific and statistical basis for quality processes. He stated:

A phenomenon will be said to be controlled when, through the use of past experience, we can predict, at least within limits, how the phenomenon may be expected to vary in the future. Here it is understood that prediction means that we can state, at least approximately, the probability that the observed phenomenon will fall within given limits. [1]

The evolution of quality management systems was influenced by experiences in World War II. During the war, individuals involved in the production of reliable products for the consumer (soldier) to effectively do their job tied the entire system from raw material to the use of the finished product in a unique “team” from start to finish. Few circumstances can link the person in production so directly to the importance of the outcome. The success of the soldier was tied to the long-term well-being of the person making the tools used by that soldier. This ability to build the tight kinship and team performance on the part of people in production to the quality of the product is the goal of quality programs in all sectors of the economy today. It is, of course, very difficult to achieve this attitude in the workplace in the same way that it could be when the outcome could so directly benefit the producers.

Following World War II, the effort of reconstruction of the industry and economy of the affected countries became a major international effort and influenced the evolution of quality programs. The work of Deming [3] and Juran [4,5], both associates of Shewart, extended his work. In 1951, Juran published a seminal book [4] that proposed the key elements for managing quality: quality planning, quality control (QC), and quality improvement. Following World War II, Deming presented a significant departure from the “standard” thinking about quality. He proposed a modification to the real relationships of quality, costs, productivity, and profit. The different approach to quality espoused by Deming is compared to the “standard” thinking in [6]. Thus, anything that improves the product or service in the eyes of the customer defines the goals of the quality program.