Proficiency testing and external quality assurance: crossing borders and disciplines

Proficiency testing and external quality assurance of medical laboratories is now entering its sixth decade. These activities comprise a broad range of applications including: providing participants and public health authorities with estimates of measurement uncertainty and national infrastructure; providing education; provision of a practical basis for accreditation and regulatory compliance. All branches of medical laboratory science have employed external quality assurance as a basis for improvement and comparability. The opportunities and challenges reviewed here include: the proper establishment of multiple target values in comparison to a system of traceability to reference or definitive methods; the problems of matrix effects and commutability of patient and proficiency test samples; generating information on laboratory infrastructure and trends in analytical technique and performance; providing education and setting goals for laboratory improvement; problems of specimen distribution; application of Internet technology; the role of programs in legal mandates and accreditation. Received: 24 April 2002 Accepted: 11 July 2002     

External quality assurance of test requesting and test interpretation

The ultimate product of the clinical laboratory is not a number, but an advice. To what quality standards should this advice live up to? In external quality assurance for primary health care in Norway, case histories are mailed together with the analytical quality control material. The analytical result of the control material is used in the case history. The feedback reports discuss clinical guidelines as well as the influence of analytical variation on clinical decision-making.     

External proficiency testing exercises on human leukocyte antigen typing in Italy between 1998 and 2002

External proficiency testing exercises are essential tools for measuring the quality of different kinds of performances related to health care and to ensure that they are uniform throughout a region. For many years, the Italian National Transplant Centre and the Italian National Institute of Health have been organizing external proficiency testing exercises for serological and genomic human leukocyte antigen (HLA) typing, following the rules of the European Federation of Immunogenetics. This society provides accreditation for immunogenetical tests to those European countries which want to collaborate on programmes on solid organ and bone marrow transplantation. The results of the Italian external proficiency testing exercises are very satisfactory because of the progressive improvement of the quality of HLA typing seen in Italian laboratories between 1998 and 2002. The attained outcome will certainly guarantee a more reliable service in clinical practice, and will contribute to the process of approaching the highest quality in health care.     

Measurement uncertainty for total ash and acid-insoluble ash determination of Chinese materia medica

The total ash and acid-insoluble ash contents of Chinese materia medica (CMM) have been widely used as one of the indices to illustrate the quality as well as purity of herbal medicines. Such an approach has also been adopted by many official organizations in writing monographs for pharmacopoeia worldwide. In the present study, a full validation on the methodology was conducted with the inclusion of various commonly encountered matrices in herbs, namely, leaf, flower, fruit, stem and root. The practice ensures method suitability for a wider scope of matrix variation in CMM. Moreover, in order to comply with the technical requirement of International Organization of Standardization 17025 quality assurance system, the concept of measurement uncertainty has also been incorporated in the present study. Measurement uncertainties for total ash and acid-insoluble ash contents have been estimated.     

A prelude of the 2004 Antwerp Quality Conference: Targets and target values—integrating quality management and costing

Questions about the value of services in the health care sector and the quality of them have been addressed frequently during the last decade, but as separate issues. In this article a method is proposed to combine these two issues. The starting point is the observation that competition will become fiercer among providers in the health care sector . Moreover, the patients opinion about quality in terms of convenience, emotional attention, etc., will be important in a competitive environment and will determine which health care service providers will be successful. These developments will have an impact on the engineering of the health care chain. Methods are discussed to integrate the determination of the value of innovations and new products, and the design of quality systems. The system of target costing is focused upon. It takes the outcome of care processes as desired by customers or the users as the starting point both for pricing the services as well as for designing the delivery system. This will not only improve cost control, but also quality improvements in two ways. First, the delivery system will be better adapted (and integrated if more health care providers are involved) to the needs of the patients, and second quality will improve as health care providers analyze, redesign, and monitor their processes more extensively.Presented at the 9th Conference on Quality in the Spotlight, 18–19 March 2004, Antwerp, Belgium     

有机锗Ge—132工艺研究

有机锗Ｇｅ－１３２是一种具有多种生理活性的功能免疫调节剂，已广泛用于保健，临床。随着各国对锗的研究不断深入，对其质量要求越来越高，从有机锗的生产角度出发，本文对原有工艺进行了许多改进，使有机锗的品质，产率，生产效率均有不同程度的提高，而生产成本大幅降低，并对原工艺不能处理的副产品进行综合回收，消除污染，取得可观的社会与经济效益。     

QASKI – the quality assurance system of the National Institute of Chemistry

 The quality assurance system (QASKI) developed and implemented in the National Institute of Chemistry is presented. It tries to eliminate the incompatibilies between the present methods of quality assurance used in research and development institutes such as good laboratory practice and accreditation. Since 1991, QASKI has been used for internal accreditation of laboratories located in the institute, regardless of the fact that some of them deal with routine analyses and others with research and development. Every laboratory that wishes to ensure the credibility of its research or routine work enters QASKI and at the same time chooses an external method of approval. All interested laboratories, study directors, principal investigators, internal auditing staff, heads of documentation, quality assurance unit staff, the Director of the institute and the Quality Management Board participate in the internal system.     

Challenges in validating the sterilisation dose for processed human amniotic membranes

Most of the tissue banks in the Asia Pacific region have been using ionising radiation at 25 kGy to sterilise human tissues for save clinical usage. Under tissue banking quality system, any dose employed for sterilisation has to be validated and the validation exercise has to be a part of quality document. Tissue grafts, unlike medical items, are not produced in large number per each processing batch and tissues relatively have a different microbial population. A Code of Practice established by the International Atomic Energy Agency (IAEA) in 2004 offers several validation methods using smaller number of samples compared to ISO 11137 (1995), which is meant for medical products. The methods emphasise on bioburden determination, followed by sterility test on samples after they were exposed to verification dose for attaining of sterility assurance level (SAL) of 10⁻¹. This paper describes our experience in using the IAEA Code of Practice in conducting the validation exercise for substantiating 25 kGy as sterilisation dose for both air-dried amnion and those preserved in 99% glycerol.     

Quality in point-of-care testing: taking POC to the next level

Point-of-care testing (POCT) is a complex system with many opportunities for error. Delivering quality POCT requires multidisciplinary coordination and an understanding of the preanalytic, analytic, and postanalytic processes that are necessary to deliver a test result and take clinical action. Most errors in laboratory testing occur in the pre and postanalytical phases and many mistakes that are referred to as lab error are actually due to poor communication, actions by others involved in the testing process, or poorly designed processes outside the laboratory's control. POCT requires significant operator interaction with analysis and documentation of calibration and quality control, unlike other medical devices. Clinicians often interpret POCT as equivalent to core laboratory testing, only faster, and mistakenly utilize the results interchangeably despite the differences in test methodologies. Taking quality of POCT to the next level involves looking beyond the analytical phase and integration of POCT into the entire pathway of patient care to understand how POCT relates to medical decision-making at specific points during the patient's care. A systematic review of the literature by the National Academy of Clinical Biochemistry is currently being conducted to draft guidelines for best practice that link the use of POCT to improved patient outcomes.Presented at the 10th Conference Quality in the Spotlight, March 2005, Antwerp, Belgium.     

Quality assurance in analytical chemical laboratories: Towards harmonization and integration of current standards

This article presents the results of a comparative study of the main quality assurance (QA) and good laboratory practice (GLP) regulation systems and standards for analytical chemical laboratories currently being applied in Europe. A growing number of laboratories are being confronted with the need to cope with two or more of these systems, which involves separate audits and inspections for certification and accreditation. As these regulatory systems have essentially the same aims, there is an increasing interest in harmonization of QA and GLP guidelines. As a first step in exploring the possibilities of harmonization, similarities and differences of the current systems, compiled in the form of cross reference tables, have been analyzed (from a laboratory practice point of view) by a study group of EURACHEM, The Netherlands. The conclusions of this study have recently been endorsed by the Committee of EURACHEM Europe.     

Sampling, sample treatment and quality assurance issues for the determination of phosphorus species in natural waters and soils

Phosphorus is an important macronutrient and the accurate determination of phosphorus species in environmental matrices such as natural waters and soils is essential for understanding the biogeochemical cycling of the element, studying its role in ecosystem health and monitoring compliance with legislation. This paper provides a critical review of sample collection, storage and treatment procedures for the determination of phosphorus species in environmental matrices. Issues such as phosphorus speciation, the molybdenum blue method, digestion procedures for organic phosphorus species, choice of model compounds for analytical studies, quality assurance and the availability of environmental CRMs for phosphate are also discussed in detail.     

Studies of radiosterilization and radiation effect on disposable medical products and their packing materials

This report describes the studies of radiation effects in the physical and chemical properties of various disposable medical products, such as catguts, syringes and theirpacking materials; toxic tests on them; sufficient radiation conditions and radiation doses. These studies could provide the basis for production of medical products and quality assurance of radiation sterilization.     

Implementation of Good Laboratory Practices (NIT-DICLA-035, Inmetro) in a technological platforms network: the Fiocruz experience

The technological platforms network (TPN) of the Oswaldo Cruz Foundation was developed as the result of the need to provide technical and scientific services to the Brazilian public health and health research networks through the use of high cost, state-of-the-art, multiuser equipment. In order to improve the quality of the services offered, a quality management system (QMS) was implemented in a group of subunits of the TPN. To achieve the planned objectives, a review of all the existing guidelines was carried out first, which led to the choice of a Brazilian guideline: Inmetro NIT-DICLA-035, ??Good Laboratory Practices?? (GLP). The next steps were the choice of the platform subunits (Pilot Project), the drafting of relevant documentation, and the creation of a quality assurance structure as well as other activities. It was clear that a proper interpretation and understanding of GLP in these platforms could make a difference in the efficacy and effectiveness of the system defined. The expertise gained through the implementation of QMS in the Pilot Project has enabled GLP implementation in the other TPN subunit platforms.     

Blood banking quality: minimum requirements for TQM

In 1995, the Council of Europe published a guide with recommendations providing transfusion services with a set of guidelines and principles relating to the preparation, use and quality assurance of blood components. As a blood transfusion service is at the same time a supplier of blood products and a test laboratory the quality management system must include good medical practice, good manufacturing practice and good laboratory service, all of which are closely linked. We made a critical evaluation of the content of the guide and analysed requirements and recommendations in comparison with quality management systems applied by the concerned partners. As a major critic we observed that the guide does not take into account any quality system of the in vitro diagnostic (IVD) supplier and/or distributor. With the addition of some items outlined in ISO 25 and ISO 9000, the Council of Europe document can be improved so that it complies with internationally accepted quality management standard recommendations.     

National External Quality Assessment Schemes for microbiology, parasitology, and virology in Europe

Quality assurance is an important aspect of laboratory management. One of the activities involved is the participation in external quality assessment (EQA) schemes by the clinical laboratory. These EQA schemes should be organised according to well-defined guidelines, such as the ESO/IEC Guide 43. The present work provides an inventory of the EQA schemes organised in Europe. The schemes are related to the fields of bacteriology, parasitology and virology. For each field various surveys have been organised. Data such as the number of participants, frequency of survey and number of samples in a survey are presented. The nature and way of manufacturing the control material is specified.     

The handbook of analytical methods for trace elements as adopted by the national reference laboratories for residues

The instrumental approaches, quality assurance schemes and management of chemical laboratories should in general be harmonized at the highest possible level. This is all the more so for the national reference laboratories (NRLs) for residues in live animals and their products which have to implement quality assurance systems inspired to the principles of good laboratory practice as well as to the general norms for the operation of testing laboratories (EN 45000 criteria). Directive 23/96/EC of 29 April 1996 prescribes that NRLs are assisted in this process by the four community reference laboratories (CRLs) for residues. To this end, the Rome CRL systematically collects in a handbook all the analytical methods in use at NRLs for the determination of As, Cd, Cu, Hg and Pb, as well as other chemical elements, in animal matrices. One major goal of this action is to foster the harmonization of analytical approaches by the NRLs and their ability to provide comparable results of similar quality. The Rome CRL is committed to revise this handbook twice a year. The role of the handbook is also to encourage the exchange of information among the NRLs as regards the possibility of improving existing methods.     

Improvements in pentosan polysulfate sodium quality assurance using fingerprint electropherograms

Complex samples from polymer production, plant extracts or biotechnology mixtures can be characterized by fingerprints. Currently, the standard approach for sample characterization employs near-infrared (NIR) spectroscopy fingerprinting. Up to now, however, fingerprints obtained by chromatography or electrophoresis could only be visually evaluated. This type of inspection is very labor-intensive and difficult to validate. In order to transfer the use of fingerprints from spectroscopy to electrophoresis, spectra-like properties must be obtained through a complete alignment of the electropherograms. This has been achieved by interpolation and wavelet filtering of the baseline signal in the present work. The resulting data have been classified by several algorithms. The methods under survey include self-organizing maps (SOMs), artificial neural networks (ANNs), soft independent modeling of class analogy (SIMCA) and k-nearest neighbors (KNNs). In order to test the performance of this combined approach in practice, it was applied to the quality assurance of pentosan polysulfate (PPS). A recently developed capillary electrophoresis (CE) method using indirect UV detection was employed in these studies [1]. All algorithms were well capable of classifying the examined PPS test batches. Even minor variations in the PPS composition, not perceptible by visual inspection, could be automatically detected. The whole method has been validated by classifying various (n = 400) unknown PPS quality assurance samples, which have been correctly identified without exception.     

Determination of polybrominated diphenylethers (PBDEs) in biological tissues with special emphasis on QC/QA measures

This paper gives an overview on the determination of PBDEs in biological tissues, such as human blood and milk, cow’s milk and fish with special emphasis on quality control and assurance measures which are mandatory and a prerequisite for a reliable determination of environmental pollutants at trace levels. First experiences in the determination of PBDEs have been gained nearly 20 years ago. Due to great progress in the development of analytical instrumentation, the applied GC/MS methods resulted in very low detection limits. Furthermore, because of unexpected findings in biological tissues, the determination of PBDEs became of growing importance in the past few years. The analysis of hundreds of samples demonstrated the need for extensive quality control/quality assurance (QC/QA) measures which will be reported in detail in the following.     

High-throughput analysis by SP-LDI-MS for fast identification of adulterations in commercial balsamic vinegars

Balsamic vinegar (BV) is a typical and valuable Italian product, worldwide appreciated thanks to its characteristic flavors and potential health benefits. Several studies have been conducted to assess physicochemical and microbial compositions of BV, as well as its beneficial properties. Due to highly-disseminated claims of antioxidant, antihypertensive and antiglycemic properties, BV is a known target for frauds and adulterations. For that matter, product authentication, certifying its origin (region or country) and thus the processing conditions, is becoming a growing concern. Striving for fraud reduction as well as quality and safety assurance, reliable analytical strategies to rapidly evaluate BV quality are very interesting, also from an economical point of view. This work employs silica plate laser desorption/ionization mass spectrometry (SP-LDI-MS) for fast chemical profiling of commercial BV samples with protected geographical indication (PGI) and identification of its adulterated samples with low-priced vinegars, namely apple, alcohol and red/white wines.     

Do we need to consider metrological meanings of different measurement uncertainty estimations?

Along the years, several approaches for measurement uncertainty estimation have been suggested. Emphasis has been put on the general metrological interpretation of measurement uncertainty, but not on its different meanings when it is associated to given conditions of measurement where analytical work is performed and errors are originated. Three different definitions for uncertainty are proposed for reproducibility and intermediate precision conditions of measurement. These definitions inherit features from the VIM 3 definition of measurement uncertainty. It is argued that if a high performance laboratory keeps errors under control with proper validation and quality assurance programs, measurement uncertainty from intermediate precision condition of measurement is justified as a suitable estimation of its capability to attribute values to a measurand. Alternatively, a laboratory that does not keep errors under control should use uncertainty from reproducibility condition of measurement as the cost of its imperfections. Selection of information sources for measurement uncertainty estimation should be in harmony with its metrological meaning.