APPLICATIONS AND EXPERIENCES OF QUALITY CONTROL Edited by Ognyan Ivanov
Applications and Experiences of Quality Control Edited by Ognyan Ivanov
Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Katarina Lovrecic Technical Editor Teodora Smiljanic Cover Designer Martina Sirotic Image Copyright Zoom Team, 2010. Used under license from Shutterstock.com First published March, 2011 Printed in India A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from
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Contents Preface Part 1
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Quality Control in Public Health and Biology
1
Chapter 1
Quality Indicators for Colonoscopy Procedures Romain Coriat, Elise Pommaret, Sarah Leblanc and Stanislas Chaussade
Chapter 2
The Need for Quality Control in High Dose Rate Brachytherapy Carlos E. deAlmeida
3
11
Chapter 3
Applications and Experiences of Quality Control to Surgical and Interventional Procedures 27 David Biau, Lionel Dessolle and Raphaël Porcher
Chapter 4
Whole Body Composition by Hologic QDR 4500/A DXA: System Reliability versus User Accuracy and Precision 45 Aldo Scafoglieri, Steven Provyn, Joanne Wallace, Olivia Louis, Jonathan Tresignie, Ivan Bautmans, Johan De Mey and Jan Pieter Clarys
Chapter 5
Quality Control in Endoscopy Unit: Safety Considerations for the Patient Jean-Francois Rey
63
Chapter 6
Development of Urodynamic Standards for Quality Control 75 Limin Liao and Werner Schaefer
Chapter 7
Guidelines for Developing Automated Quality Control Procedures for Brain Magnetic Resonance Images Acquired in Multi-Centre Clinical Trials 135 Elias Gedamu
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Chapter 8
Quality Control in the Early Secretory Pathway Plays Significant Roles in vivo 159 Tomohiko Aoe
Chapter 9
Quality Assurance in the Preanalytical Phase 185 M. Antonia LLopis, Virtudes Alvarez, Cecilia Martínez-Brú, Rubén Gómez, Núria Barba, Mercè Ibarz, Mariano Cortés, Montserrat Ventura and M. Jesús Alsina
Chapter 10
The Need for Quality for Better Laboratory Performance, Alexandria University Experience 205 Mohamed Moustafa Rizk, Abla Abou Zeid and Nermine Hossam
Chapter 11
Quality Control for the Molecular Diagnosis of Toxoplasmosis 217 Emmanuelle Varlet-Marie, Yvon Sterkers and Patrick Bastien
Chapter 12
Quality and Safety in PICU and NICU: Scoreboard Control and Care Network 233 Fuster-Jorge, P.A., Fernández-Sarabia, J., Delgado-Melián, T., Pérez-Hernández, R., Jiménez-Rivera J.J., Montes de Oca-Afonso M.R., Domenech-Martínez, E. and Sierra-López, A.
Chapter 13
Primer Design to Sequence Analysis a Pipeline for a Molecular Genetic Diagnostic Laboratory 257 Elaine Doherty, Renate Marquis-Nicholson, Jennifer M. Love, Clare Brookes, Debra Prosser and Donald R. Love
Chapter 14
Innovative Approaches in Quality Management in Clinical Laboratories 273 Lina Souan, Maher A. Sughayer
Part 2
Computer and Mathematical Approaches for Quality Control 295
Chapter 15
Mathematically Fuzzy Approach to Quality Control Rostovtsev A.M.
Chapter 16
On Some Applications of Nonlinear Differential Equations in Image Processing: Concepts and Electronic Implementation 315 S. Morfu and P. Marquié
Chapter 17
Quality Control in Clinical Laboratories 331 Petros Karkalousos and Angelos Evangelopoulos
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Chapter 18
Water Quality Control from the Perspective of Water Supply System Users’ Safety 361 Janusz Ryszard Rak and Barbara Tchórzewska-Cieślak
Chapter 19
The Application Research of Intelligent Quality Control Based on Failure Mode and Effects Analysis Knowledge Management Zhao Xiuxu
375
Chapter 20
Model Driven Adaptive Quality Control in Service Oriented Architectures 381 Tomasz Szydło and Krzysztof Zieliński
Chapter 21
Research about New Predictive-Maintenance Methodology using VBA for Marine Engineering Applications 397 José A. Orosa, Angel M. Costa and Rafael Santos
Chapter 22
Development of VBA Based Ship Technical Corrective Management System for Marine Engineers 411 José A. Orosa, Angel M. Costa and Rafael Santos
Chapter 23
Quality Assessments of Seafloor Mapping with Multibeam Echo Sounders Jan Terje Bjørke and Stein Nilsen
Part 3
425
Quality Control in the Industry 449
Chapter 24
Electrochemical Methods in Analysis of Biofuels André L. Santos, Regina M. Takeuchi, Paula G. Fenga and Nelson R. Stradiotto
Chapter 25
Quality Control Implementation in Manufacturing Companies: Motivating Factors and Challenges 495 Hairulliza Mohamad Judi, Ruzzakiah Jenal and Devendran Genasan
Chapter 26
Quality Control Methods Based on Electromagnetic Field-Matter Interactions Ognyan Ivanov and Mariana Kuneva
Chapter 27
Process Monitoring of Polymer Systems by using Near-Infrared Spectroscopy 537 Wei Li
Chapter 28
Digital Image Processing for Quality Control on Injection Molding Products 555 Marco Sasso, Massimo Natalini and Dario Amodio
451
509
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Chapter 29
Power Quality Control in Wind/Fuel Cell/Battery/Hydrogen Electrolyzer Hybrid Micro-grid Power System 579 Xiangjun Li, Dong Hui, Xiaokang Lai and Tao Yan
Chapter 30
A Discussion on Current Quality-Control Practices in Mineral Exploration 595 Armando Simón Méndez
Chapter 31
Sampling Errors and Control of Assay Data Quality in Exploration and Mining Geology Marat Abzalov
611
Chapter 32
Adaptive Calibration and Quality Control of Smart Sensors 645 Matej Možek, Danilo Vrtačnik, Drago Resnik, Borut Pečar and Slavko Amon
Chapter 33
Hyperspectral Imaging for Raw Material Sorting and Processed Product Quality Control 663 Pilar-Beatriz García-Allende, Olga M. Conde and José Miguel López-Higuera
Chapter 34
Quality Control of the Microlenses Array Rafał Kasztelanic
687
Preface Quality control is a principle which has become a part of our way of living. One can even say that it is present everywhere in the world around us. Quality control is a process that every one of us does voluntarily and involuntarily. We carefully choose our food, clothes and the environment that we live and work in. Even our bodies have quality procedures and if they don’t like something there is always some kind of symptom. Our cells check every macromolecule and protein they produce, thus ensuring our wellbeing. But what is quality control? It is a process selected to guarantee a certain level of quality in a product, service or process. It may include whatever actions a business considers as essential to provide for the control and verification of certain characteristics of its activity. The basic objective of quality control is to ensure that the products, services, or processes provided meet particular requirements and are secure, sufficient, and fiscally sound. Essentially, quality control requires the examination of an entity for certain minimum levels of quality. An essential aim of quality control is to recognize products or services that do not meet a company’s specified standards of quality. If a problem concerning quality control is detected, temporal interruption of production may be required. Depending on the particular service or product, as well as the type of problem identified, production or implementation may not cease entirely. Competition, technological progress, new customer requirements and other factors have forced many companies to start applying total quality management. The aim of this approach is the increase of the efficiency and competitiveness of each and every product through a customer satisfaction quality criterion. By “quality”, not only the technical characteristics of a product or service are meant, but also the capability to meet customer requirements, a reasonably low cost, continuously maintained high quality, etc. The quality of the product or service is a sum of two components: technical characteristics and customer service. Particularly from a customer’s point of view quality means: perfect customer service, high technical parameters, low price and more. Meeting such high demands is achieved through application of technical and scientific methods which ensure on one hand, quality, and on the other hand - low production costs and optimal usage of resources, time, energy, etc. The main goal in total quality control is to prevent mistakes, weaknesses or deviations, especially in the initial planning of an activity applying to the functioning of a system, organization, product or service. In this context, quality control can be defined as the
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sum of functional procedures, confirming the quality of a product or service, based on particular specifications. An important component of quality control is the control during the production of a device. It is essentially a comparison of a product to certain specifications, which has gradually evolved into a collection of methods and techniques known as quality control. The classic approach to quality control is based on this control during production (tests, measurements, etc.) of the device after its manufacture and removal of defects. Quality control recognizes defects in the planning and construction of a product, whereby the defective units can be found out and repaired. The development of production is an ever changing process to some extent and there are variations in the manufacturing specifications. Because of these variations there needs to be a probability model and statistical methods for product quality analysis. If all major sources of variation are under control during the manufacturing process, i.e. if there is good quality control, then no serious problems arise. It can generally be said that there are three types of control: preliminary - focuses on preventing inconsistencies; real-time control - monitors any operations taking place; control through feedback - a corrective procedure aimed at improving either the process of regulating the production resources, or the actual operations during production. Quality control can deal with not just products, services and processes, but also people. Employees are a crucial factor in any company. If a company has employees that don’t have sufficient competence and techniques or training, have difficulty comprehending directions, or are inexperienced, quality may dangerously decline. When quality control is regarded in terms of human beings, it relates to correctable issues. A leading aspect of quality control is to determine well-defined controls. These controls help standardize both production and responses to quality concerns. Confining possibilities for error by specifying which production activities are to be completed by which personnel decreases the chance that employees will undertake or be assigned tasks for which they do not have adequate training. Quality control can be achieved by the following common steps: establish what parameter is to be controlled; ascertain its importance and whether it needs to be controlled before, during or after results are produced; determine a specification for the parameter to be controlled which provides limits of acceptability and units of measure; develop strategies for control which specify the methods by which the characteristics will be achieved and variation detected and removed; coordinate resources to accomplish the strategies for quality control; install a sensor at an applicable point in the process to detect variance from specification; gather and transmit data to a location for analysis; verify the results and identify the cause of variance; suggest solutions and select the procedures needed to restore the usual parameters; perform the agreed procedures and confirm that the variance has been corrected. The quality control can be divided into three major parts. One part consists of the procedures to determine an optimum level of performance analysis by professionals. The proper supervision over field work, assessment of internal control, and exercising commonly accepted auditing standards are also considered. The monitoring of a company’s system of quality control by a peer reviewer incorporates examination of the effectiveness and relevance of the company’s procedures, practices and conformity
Preface
thereto, potential for professional development, and quality of the company’s practice aids. Another part is the practices and methods used to affirm that some level of performance has been attained. Controls in design and inspection are included. Variances from established standards are discovered and corrected. The last part comprises procedures in manufacturing to deliver a chosen level of satisfaction of the service or product that is being developed. A certain amount of experiments and evaluations may be required to certify that a product, service or process meets the desired requirements. Most manufacturers would always disregard the possibility of excluding the quality control as a part of their production processes. Without quality control, the number of defective products that must be modified, demolished or sent back would significantly increase. Almost all service organizations observe closely the quality of the services they deliver to maintain their reputations, guarantee the satisfaction of their customers. After all, nobody would keep a product that disintegrates the day after it is purchased or choose a service that hasn’t provided some guarantees for its quality. For instance, lowering the quality of any given procedure at any health center may lead to a fatal end for a great number of patients. New communication technologies provide new opportunities for quality control. Systems for electronic tracing of the source and whereabouts of a product are developed. Certain categories of products including food, cosmetics and household appliances cannot be sold without identification and tracking codes. Customers can obtain information about each product by entering its code in a particular Internet address or by phone. Such a system is currently implemented in China. This is an important step to ensure product quality. Quality control is an important component of management and related policy. The purpose of this policy is to comply with the requirements of customers through the stages of the manufacturing cycle of a product without wasting material, financial or personal resources of the enterprise. Product quality is the result of careful planning, impeccable execution and consistent control. The goal in planning the quality is in all stages from the creation to the application of the product to address as accurately as possible all quality related problems, issues and expenses. In this context, quality control is establishing whether a product satisfies the quality requirements. In the case given, the parameters affecting the quality of the finished product are being tested. Quality control is the basis for regulating the quality and the quality assurance. Regulation of quality includes the activities to prevent errors, control and adjustment of processes in the production order, so that the quality requirements can be met. Typical for the regulation of the quality is that it lies in the planning stage and uses the test results of the quality control. The quality assurance activities include establishing a trust for the fulfillment of quality requirements through the systematic presentation of the ongoing events in an enterprise quality management in various stages of the manufacturing process. The system of quality management must have a leading role with respect to all other systems. It plays an important role for the quality control department. This department is independent from other departments. Its task is to assist and coordinate the
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activity of quality management. It conducts the inspection of the processes, the quality improvements and improves the quality-related costs. This is done through periodic sampling, checking product quality, writing reports for the plant management and proposals for improving production quality. During certain periods, it inspects the activities of the quality system and establishes whether the system complies with the requirements. This department does not assume full responsibility for production quality. It must ensure the optimal functioning of the quality system by direct assignment of management. As mentioned at the beginning, quality control is a very broad topic, which is present in areas very distant from each other. In this book some of the quality control aspects in the public health care, biology, mining, processing and manufacturing industry, the development of sensors for quality control and some of the computer and mathematical approaches are reviewed. The chapters in the book are divided into three sections: Quality control in Public health and Biology, Computer and Mathematical approaches for Quality control and Quality control in the Industry. In public health, the quality of the procedures performed is of highest importance. There are different errors than can be made, human error being the more common. But human errors can be avoided with proper training and strict quality control. The quality of the lab results can be of a crucial significance for the wellbeing of the patient. With the proper procedures, the accuracy of the laboratory equipment can be brought to high levels, but if the samples are not properly acquired the apparatuses will give false results that can be fatal to the patient. So, the pre-analytical quality control is of great importance. In section Quality control in Public health and Biology, the topics that are referred to below are introduced. In the book, the necessity to choose the reliable indicators of the quality of new techniques for colonoscopy procedures is examined. The goal is to choose a limited number of quality criteria that now appear unavoidable and must be systematically evaluated (indication of the colonoscopy withdrawal times, patient consent, comorbidities, quality of preparation, cecal intubation, rate of adenoma by colonoscopy, immediate complications). The physical aspects of quality control in brachytherapy are discussed, and how essential it is that the medical physicists possess the knowledge and skills necessary to make the sometimes delicate decisions concerning this type of approach. Presented are the challenges brought by the application of quality control methods to surgical procedures in cardiac surgery, general surgery and orthopaedic surgery and interventional procedures such as endoscopy, anaesthesiology, and reproductive medicine. Safety considerations for the patient related to endoscopy are also introduced. They include the mandatory use of a protocol for all parts of endoscopy procedures, control in the endoscope maintenance and the importance of auditing in the endoscopy unit. Reviewed are a number of problems related to Dual energy X-ray absorptiometry applications resulting from body composition terminology and data acquisition validity.
Preface
Dual energy X-ray absorptiometry is principally designed to provide information for the accurate diagnosis of osteoporosis, but also determines the whole body composition. Described are two strategies in two stages that are used to develop urodynamic standards for quality control. Those strategies involve the establishment of a tool for quantitative plausibility check and quality control, and another tool for qualitative plausibility check and quality control. The two stages include quality control during urodynamic investigation and that of retrospective analysis. Guidelines for developing automated quality control procedures for brain magnetic resonance images acquired in multi-center clinical trials are provided. The emphasis is placed on demonstrating the need for appropriate quality control procedures, defining quality, determining the objectives, developing a framework to facilitate the creation of quality control procedures for magnetic resonance images, and methods to design, develop, test, and validate quality control procedures. Studied are the physiological and pathological roles of an endoplasmic reticulum molecular chaperone and folding enzyme, binding immunoglobulin protein, based upon several in vivo studies in mammals, which may reveal diverse functions of endoplasmic reticulum quality control in vivo. Analyzed is the significance of quality assurance in the pre-analytical phase, which includes all processes from the physician’s request for laboratory test to the moment the sample is ready for testing, since any errors that occur at this stage often become apparent later in the analytical and post-analytical phases. Alexandria University clinical laboratories share their experience with the critical factors, involving the imprecision, inaccuracy, and instability of a measurement procedure, as well as the error detection and false rejection characteristics of a statistical quality control procedure that affect the quality of laboratory test results. Explained is the demand for external quality assessments as the only way to homogenize the level of performance of the molecular diagnosis of congenital toxoplasmosis among laboratories in France. Presented is a summary of two processes that can improve the quality and safety of the pediatric and neonatal intensive care units: the detection of nosocomial infections and early use of end respiratory pressure support and noninvasive ventilation in newborn infants of very low birth weight. Represented is an overview of the requirements in quality control and quality management in certified clinical laboratories as well as a description of the different stages in clinical testing procedures and a highlight on the critical steps that need to be monitored via quality assurance indicator tools. Conducted is a study to design suitable M13-tagged primers to amplify the coding exons of any human gene following standard buffer and cycling conditions and adopting the Applied Biosystems software package, Variant Reporter®, to enable high throughput quality-controlled sequence analysis.
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In order to increase the quality control, some computer and mathematical approaches should be applied. They are cost-effective and easily maintained once properly implemented. These approaches greatly lower the probability of human error and increase the precision of the tests. In section Computer and Mathematical approaches for quality control, the topics that are referred to below are introduced. A mathematical model is required for unbiased quality control. In practice, in the absence of databases (which happens during design and development of new products), it is convenient for mathematically imprecise quality control to refer to probability assignment functions, the basis of which is some or another differential law of distribution, and in the first place – the Gaussian function. Such reference enables to note that probability assignment functions synergistically integrate the approach based on probability theory and mathematically imprecise approach to quality control. The properties of nonlinear differential equations for image processing purposes are studied, and more precisely - contrast enhancement, noise filtering or image segmentation, which constitute the most common pre-processing tasks performed to enhance pattern recognition and classification applications. Nowadays the laboratory results of the clinical laboratories are determined by automatic analyzers. In terms of quality control, it is obvious that checking the reliability of each laboratory result is unavoidable. Quality control can be performed only for the equipment and the analytical methods. The only way to do this is to check the reliability of certain samples which are running on the analyzers with the analytical methods of the laboratory. The whole procedure is called “statistical quality control”. Water quality control from the perspective of water supply system users’ safety contributed to create drinking water production and quality control procedures. The system of hazard analysis concern critical control points and its main principles have been described. An approach which combines a statistical process control system with potential failure mode and effect analysis repository can help determine the operators’ decision-making process when a quality problem has been detected. The prototype named “intelligent quality control system” has been developed, and its application shows that the efficiency of quality control can be improved. This system provides an effective way for manufacturing process continuing improvement. A complete picture of model-driven adaptive quality control in service-oriented architectures is provided, starting with the concept of quality of service and quality of experience management. The primary goal of this research is quality of service and quality of experience control in complex software systems under changing business processes execution requirements. New predictive-maintenance methodology that is optimal for developing a qualitycontrol analysis of attributes is researched. Results show that Visual Basic for Applications (VBA) for marine engineering applications is the most adequate language that can reduce the programming time and is compatible within the available limited resources.
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Illustrated is a VBA-based ship technical information management system that has been developed for application during the ship’s working periods, and tested in real ship conditions by experienced marine engineers. Results reveal real improvement in corrective maintenance like failure detection and location of replacement parts in the storage room. Methodologies to perform quality assessments of seafloor relief mapping with multibeam echo sounder are explained. The final product in seafloor mapping is often a digital elevation model. From this model, different cartographic products can be derived, such as contour line maps, perspective views, shaded relief maps or maps with coloured depth intervals. Since the construction of a digital elevation model can be based on different interpolation methods, an assessment of common methods is also presented. In industry, the quality of a product is as important to the customer as it is to the manufacturer. Increasing the quality of the manufacturing process increases the quality of the product and lowers the waste, thus lowering the price. The control should be exerted on all stages of the production process: acquiring the raw materials, their processing and the manufacturing of the finished product. In section Quality control in the Industry, the topics that are referred to below are introduced. The growing use of biofuels has triggered an increasing demand for analytical methods that allow the monitoring of their quality. The electrochemical analytical methods (potentiometric, conductometric, coloumetric, voltammetric and amperometric) generally have a high detectability, high portability and a comparatively lower cost compared to other methods, and that is why they are presented in this book. There is also an increasing need to find the right system to appropriately distribute the power generated from all renewable energy sources. What are the components of one such particular micro-grid power system and what are its main advantages is also described. Addressed is the implementation of quality control in manufacturing companies and how the application of quality control helps the companies to ensure high quality and reliable products according to the needs of the customer. The need to increase the quality of their products forces manufacturers to increase the level of control on finished and semi-finished parts, both qualitatively and quantitatively. The adoption of optical systems based on digital image processing can be a cheap but versatile way to conduct quality control by on-contact inspection of injection-molded parts. Introduced are the applications of near-infrared spectroscopy to monitoring the polymers’ polymerization, processing, curing and production of polymer prepregs. For each application, the principle, the operation method and the results are described in detail. Field-matter interactions are very attractive for practical applications in contactless and rapid analysis. Two types of effects, induced by irradiation with electromagnetic waves, are considered: acoustoelectric effect and surface photo-charge effect, together with the possibilities for their application in a large area of quality control activities. Experimental approaches and set-ups for detecting the studied effects are described as well as the main experimental results, highlighting the advantages and disadvantages of the quality control methods based on them.
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The best quality control practices are compared with some current practices observed on international exploration and mining projects, and their direct implications on resource estimation and classification are discussed. Modern mining projects use hundreds of thousands of samples for obtaining quantitative characteristics of the geological attributes. Sampling errors can appear at any stage - planning sampling program, samples extraction, preparation and their eventual analytical assaying. A special quality control technique commonly used in exploration and mining geology for verification of mineralization grades, and its basic principles are demonstrated. The design and implementation of a smart calibration system based on a manifold absolute pressure sensor as an example for automotive application is demonstrated, although the proposed approach can be extended to other types of sensors. A concept for a novel, closed-loop calibration system, which enables analysis of sensor properties and optimization of the calibration procedure, is presented. There is a demonstration of hyperspectral imaging spectroscopy which integrates conventional imaging and moderate resolution spectroscopy, and of the feasibility of spectral imaging for the high speed, in-line inspection and enhanced quality control essential in commercial and industrial applications; it is accompanied by a discussion on the difficulties that may arise from real scenarios such as deviation in the illumination spectrum or instabilities in the background radiation. An optical setup for automatic quality control of microlens arrays is shown together with the results of its computer simulations and experimental creation, and the setup’s main assets and drawbacks are summarized. The rich palette of topics set out in this book provides a sufficiently broad overview of the developments in the field of quality control. I hope this issue will be beneficial to all professionals with an interest in this field, regardless of their specific expertise. By providing detailed information on various aspects of quality control, this book can serve as a basis for starting interdisciplinary cooperation, which has increasingly become an integral part of scientific and applied research.
Ognyan Ivanov Georgi Nadjakov Institute of Solid State Physics (ISSP) Bulgarian Academy of Sciences Sofia, Bulgaria
Part 1 Quality Control in Public Health and Biology
1 Quality Indicators for Colonoscopy Procedures Romain Coriat1,2, MD, MSc, Elise Pommaret1,2, MD, Sarah Leblanc1,2, MD, and Stanislas Chaussade1,2, MD, PhD 1Service
de Gastroentérologie, Hôpital Cochin, GHU Ouest, Paris, 2Université Paris Descartes, Paris, France
1. Introduction Colonoscopy remains the gold standard for morphologic colon. Despite the development of new methods of morphologic bowel, colonoscopy is still considered the « gold standard » because of its ability at detecting small neoplasic lesions as well as adenomas. Unlike other methods, colonoscopy has the great advantage of carrying out the same time the removal of polyps. Colonoscopy also has a number of limitations. Studies have confirmed that the colonoscopy examination was an improvement over the performance review that fluctuates depending on the quality of it. Thus Pickardt et al showed that colonoscopy could miss up to 10% of polyps greater than 10mm (1). Also, it should be noted that interval cancers after colonoscopy is not uncommon (2). These results underpin the idea that colonoscopy is an examination of improvement and it is necessary to define quality criteria. The most famous of all is the detection rate of adenoma. This simple criterion was used to compare the performance of endoscopists (3). To reduce variation between endoscopists and to generalize the practice of colonoscopy quality, we must have reliable and easily measurable criteria for assessing the quality of examinations. These criteria should ensure that consideration is medically justified. It is carried out by using standard validated, that lesions are diagnosed correctly and appropriate treatments are made. All of it should be done with minimal risk to patients. Moreover, these criteria must evaluate the entire examination and not just the technical act. Those criteria must also take into account: the information provided to the patient, risk assessment, and conditions of the act. Indications for colonoscopy and appropriate intervals have been established by the taskforce in 2006 between the American College of Gastroenterology and the American Society of Digestive Endoscopy (4).
2. Quality criteria before colonoscopy Indication Indications for colonoscopy vary by country, particularly in terms of policies in place for colorectal cancer mass screening. In France, in contrast to the USA, screening colonoscopy is not recommended for mass screening, that is to say persons without familial or individual risk factors. But it is recommended for persons in high or very high risk of colorectal cancer.
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Applications and Experiences of Quality Control
Colonoscopy surveillance is warranted consideration by the patient's personal history, such as a history of polypectomy for adenoma, or a history of colorectal cancer. In France, diagnosis colonoscopy is justified when there are digestive symptoms or if the screening test (Hemoccult ® test) is positive. Indications list for colonoscopy must be validated by an expert committee and must be clearly indicated in the report of examination. An audit carried out in France in 2006-2007 has shown that the colonoscopy indication was consistent with the recommendations of the ANAES in 94% of cases (5). Risk factors for complications Colonoscopy is an examination potentially at risk. This risk must be assessed by endoscopist. Quality criteria should take into account the ground, comorbidity, current treatments include anticoagulant and antiplatelet agents. Informed consent, including information on risks of the examination must be obtained in all cases. The gastroenterologist, possibly with the assistance of the anesthesiologist must identify possible risk factors related to land and salaries made by the patient, including anticoagulants or antiplatelet agents that need to be managed with the help of cardiologists. (6, 7). It is the same for antibiotic prophylaxis. American Society of Anesthesiologists (ASA) score risk assessment anesthetic could be a simple criterion of evaluation of gesture. ASA score or "Physical status score" was developed in 1941 by American Society of Anesthesiologists. This score assesses both risk of anesthesia and predict mortality and perioperative morbidity. Ideally this score should be briefed on the report of colonoscopy, as well as taking antiplatelet or anticoagulant treatment, and implementation of prophylactic antibiotics. Block and the staff of endoscopy There were many recommendations on traceability of the material over the past 10 years. This aspect is now under control and regular monthly monitoring. To justify the validity of washing, the date and time of washing equipment must be indicated on the record. Similarly, any use of disposables or not must be indicated on the record with reference material used.
3. Quality criteria related to the procedure The quality of bowel preparation The quality of the preparation has been a recent development (8). If the quality of preparation for colonoscopy is arguably dependent patients, it does not mean totally independent gastroenterologist. It is the responsibility of preparing gastroenterologist adjusted according to the patient to be considered good bowel preparation in review. (Picture 1a,b,c) The gastroenterologist must explain why the patient issues of preparation is mandated and how to get a good preparation of the colon. The impact of colon cleanliness assessment on endoscopists’ recommendations for follow-up colonoscopy has been evaluated by Ben-Horin et al (9). They showed that clinical évaluations of the colon cleanliness vary considerably among endoscopists. Also, poor preparation exhibited at risk of missing lesions (10), to extend the duration of the examination and have an incomplete review. This might explain in part the observed differences in performance between endoscopists. The type of bowel preparation used, and any difficulties encountered by the
Quality Indicators for Colonoscopy Procedures
5
patient to prepare (nausea, vomiting, failure to take prescribed amount in full) should be included in the record review. It would take them into account when the next review, and avoid the failures of preparation at the 2nd colonoscopy (11). The difficulty is that there is no standardized system for evaluating the quality of preparation, to define what an inadequate preparation, and at what point should repeat the test. It was shown that while 23.4% were deemed unprepared colons by endoscopy, colonoscopy was considered to redo that 6% of cases (11). In other cases insufficient preparation of the colon, are known to gastroenterologists tend to shorten the interval between examinations (9), without, however, this attitude has not been validated (12). Another difficulty is the subjective nature of interpretation. While it is well established that the same preparation can be evaluated differently by endoscopists (9), it is interesting to note that endoscopists with the best performance are generally the most demanding quality the bowel preparation (13). The rate of complete colonoscopy A colonoscopy is called complete when the endoscope has reached the cecum. We can be certain of having reached the lowest depths when cecal ileocecal valve and appendiceal orifice was clearly visualized. In case of doubt, the valve must be crossed. Reaching the bottom caecum should be stipulated in the record review. The average rate of complete colonoscopy must be calculated annually by the gastroenterologist and / or the endoscopy unit to which he belongs. According to U.S. guidelines, the rate of complete colonoscopy should be above 90%, and 95% for colonoscopy screening (4). The reasons for the failure of cecal intubation should be included in the report. It may be the poor quality of bowel preparation, technical difficulties related to the anatomy of the colon, the existence of a marked diverticulosis, sedation insufficient, or because of stenosis. The detection rate of adenomas This is the best criterion for quality of colonoscopy, because it is the purpose of this examination to diagnose and to resect colorectal neoplasic lesions. According to U.S. guidelines, the detection rate of adenomas should be greater than or equal to 25% in men and 15% of women submitting to a first screening colonoscopy after 50 years (4). Recently, the detection rate of adenoma has been recognized as the main criterion of quality of colonoscopy. Similarly, the authors acknowledge that this criterion of quality allowed to decrease the risk of interval cancer (14). The detection rate of adenomas is an indicator still difficult to be applied by all gastroenterologists or all endoscopy centers, for histological data are not available at the time of writing minutes of colonoscopy. Circumvent this difficulty involves the availability of suitable software to return to reporting and enrich it with pathological results. A standardization of this test is possible with a possible justification for the quality of the endoscopist by this single criterion like the "pay-forperformance" in force in the U.S. (15). The time of withdrawal of the endoscope It is the study of Barclay et al. (16) which attracted particular attention on the relationship between detection rate of adenomas and time of withdrawal of the endoscope. The authors reported detection rates of adenomas among endoscopists significantly different according to whether they had a withdrawal time greater or less than 6 minutes. The withdrawal time was used as a quality criteria and is now consider as a criteria in colonoscopies without injury.
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Applications and Experiences of Quality Control
This study confirmed the work from the Mayo Clinic showed that 50% of polyps were diagnosed an average withdrawal time of 6.7 minutes, and 90% of polyps to a withdrawal time of 12 minutes (17). A recent observational study conducted among 315 gastroenterologists practicing in 17 U.S. states has confirmed the results of Simmons et al. study, showing that those with an average withdrawal time equal to 6 min detected 1.8 times more polyps than other (18). A different question is whether the application of rule 6 min. is likely to improve the performance of endoscopists. A work of Barclay et al. (19) has responded positively to this question. He was asked to 12 endoscopists to have a withdrawal time of at least 8 minutes, that is to say, look for at least 2 minutes each of four segments: right colon, transverse, left, and rectosigmoid. The performance obtained after introduction of the recommendations were compared to those recorded during a previous period. In this study it was observed significant increase in performance of endoscopists in terms of rate of colonoscopy with adenomas, number of adenomas or advanced adenomas by colonoscopy (19). Conversely, a study group in Boston has shown that the establishment of an institutional policy requiring a withdrawal time equal to 7 minutes did not alter the performance of a group of 42 endoscopists performing more than 23,000 colonoscopies (20). Another study of 43 gastroenterologists in two cities in Minnesota concluded the same way the lack of improvement in performance over time despite awareness programs (21). Moreover, the interpretation of an average time is difficult when performing colonoscopy. It is therefore useful to estimate its average withdrawal time as recommended by the American College of Gastroenterology (4) but do not consider the withdrawal time of less than 6 minutes in a patient as a cry of poor quality examination. The threshold is an average of 6 minutes, and not a criterion required for each examination. If the withdrawal time is not longer a guarantee of performance, it is nevertheless witnessed a conscientious and thorough examination, and is likely to improve its performance. In total, if a withdrawal time of less than 6 minutes should not be considered at the individual level as a criterion of poor quality, a time longer than 6 minutes may be a factor in favor of a careful examination and quality. For this, the withdrawal time of colonoscopy and the total time of the review should be indicated on the record. The Record Review It must contain certain information relating to prior colonoscopy criteria (indication, sedation, quality of preparation, ASA score, total time of examination, removal time and comorbidities), information relating to the review (cecal intubation , number of polyps sized location, treatment biopsies), but also information on the after colonoscopy (what to do, operative risk). Lesions should be described precisely (number, location, shape, size). Complications Serious complications of colonoscopy such as perforation, or those of endoscopy in general, should be regularly recorded by endoscopy center, and be discussed. Immediate complications are easily identified in the report of the review. The latest series of the literature showed that the rate of perforation secondary to colonoscopy is currently the order of 1 case of perforation from 1000 to 1400 examinations (22). Lower rates (1 per 4900 examinations) have been reported recently in Germany in a series of 269,000 colonoscopies (23). Three quarters of the perforations are diagnosed immediately or early (
