Addressing issues associated with the development and management of PT programs and with their optimum use

Over 200 participants from 54 countries took part in working group (WG) discussions on proficiency testing (PT) held in conjunction with the Global Odyssey 2002 conference on 24–26 February, 2002 in Atlanta, Georgia, USA. Each WG addressed a series of questions focusing on the role of PT in laboratory quality management (WG1), alternatives to traditional PT (WG2), international aspects of PT programs (WG3), quality management of PT programs (WG4), how to assess laboratory performance (WG5), and developing and funding PT for resource-limited countries and regions (WG6). Each large WG was further subdivided into smaller groups to allow maximum participation, which was one objective of the WGs. Some subgroups addressed the same questions, but in most cases they drew very similar conclusions. Individual participants were surprised to discover the truly global nature of some problems with PT, while at the same time how specific differences among countries or regions can either enhance or hinder opportunities to implement PT programs. Received: 13 April 2002 Accepted: 25 April 2002     

External quality assessment schemes for clinical analysis in Russia

 The history and the present condition of external quality assessment (EQA) schemes for clinical laboratories in Russia are described briefly. The creation of EQA programmes started in Russia in the 1980s. Now almost 20 years later these schemes have been transformed. The National External Quality Assessment Scheme ensures quality control in the clinical chemistry sector (more than 2000 laboratories) and is the most powerful scheme in Russia. The (Sistema Vneshnego Kontrola Katchestva, *) (BKK) system, covering about 120 Russian laboratories, and a lot of local regional programmes (mainly in Siberia), is also very active. The purposes and design of the operating programs, reference materials used, algorithms of estimation, modes of result representation and development prospects are considered. The basic obstacle to the development of EQA schemes in Russia is financial restriction.     

The Swiss External Quality Assessment Scheme in Bacteriology and Mycology 1992–1996

 The Swiss External Quality Assessment Scheme in Bacteriology and Mycology was created in 1980 and has been organised since 1983 by the Department of Medical Microbiology in Zurich. The number of Swiss participants has steadily risen from 66 in 1989 to 92 in 1996. Twelve bacterial and fungal strains are sent to the participants in four despatches, each containing three specimens, per year. Scores are allocated per specimen and range between 0 and 1. Participants with mean scores of ≤0.75 are considered poor performers. The mean scores increased from 0.85 in 1992 to 0.91 in 1996. This improvement can be attributed to the educational effect of the external quality control scheme, since all participants receive a detailed discussion for each specimen together with their individual results. On average, both large University and Cantonal (state) laboratories as well as private laboratories show satisfactory performance. In particular, laboratories officially recognised by the Swiss Federal Office of Public Health (SFOPH) rate better than non-recognised participants. Many small regional hospital laboratories, most of them not SFOPH-recognised, are often among the poor performers. They are often managed by technical staff and lack a trained microbiologist. The recently introduced legislation in Switzerland renders participation in external quality assessment schemes compulsory, and all clinical microbiology laboratories are required to employ qualified microbiologists. This will certainly help to improve the quality standards of all laboratories performing microbiological tests. Received: 13 November 1997 · Accepted: 28 December 1997     

Quality assurance programs for countries in need: a global view from the College of American Pathologists

Providing laboratory external quality assessment (EQA) programs for countries in need requires special considerations not ordinarily part of EQA for laboratories in industrialized countries. Cultural, professional, service and economic factors must be understood and accommodated in order to carry out successful programs. Coordination of worldwide efforts for countries in need requires more resources and planning than have thus far been devoted to the enterprise.     

Quality assurance in clinical chemistry laboratories in the UK

 Since the mid-1960s quality assurance in clinical chemistry has progressed from a need to define and improve precision and accuracy in analytical test procedures to an all-embracing process of assuring that the whole process of pre-analytical, analytical and post-analytical phases of handling patient samples is managed effectively and efficiently. Automated and computer-controlled equipment has reduced many of the analytical errors, in particular in imprecision, that were present in manual analysis. New management techniques have been developed to control the quality and appropriateness of results. Developments in internal quality control and external quality assessment procedures have enabled laboratories to continually improve the quality of assays. Laboratory accreditation and external quality assessment scheme accreditation have ensured that peer review and peer pressure have been applied to both laboratory and external quality assessment scheme performance. As the NHS reviews its priorities and places more emphasis on primary care provider demands, hospital laboratories will of necessity assist with near patient testing outside the laboratory. This will provide new challenges to the quality of the service provided. Received: 2 July 1998 · Accepted: 1 August 1998     

External quality assurance programmes in medical laboratories

 Medical laboratories have a long tradition of external quality assessment. Starting from pure quality control of laboratory performances, most schemes have evolved to a powerful tool for improving quality of clinical outcome of results. External quality assurance in medical laboratories not only includes laboratory performance evaluation, but also evaluation of method performance, post-marked vigilance, training and help. In the future, the quality of programmes must further be improved by accreditation of schemes and by using electronic data interchange. Received: 9 December 2000 Accepted: 14 December 2000     

Anti-HIV quality assurance programs in Australia and the southeast Asian and Western Pacific regions

Anti-HIV testing is the most regulated area of laboratory medicine in Australia. These regulations have placed the National Sero-logy Reference Laboratory, Australia (NRL) in a unique position to implement a comprehensive quality assurance (QA) program for HIV testing. The elements of our QA program include pre-market evaluation of assays, external quality assessment schemes (EQAS), quality control, specificity monitoring, consultations, and training workshops. The results of the NRL EQAS for Australian laboratories were compared with those of a program developed by the NRL for reference laboratories in the Southeast Asian and Western Pacific (SEAWP) regions. For laboratories authorized to use tests for HIV in Australia, participation in the entire QA program is mandatory, whereas the SEAWP EQAS program is voluntary. While the overall percentage of discrepant results for these programs are similar, the percentage of false negatives, variation in laboratory results, and choice of assay differ. These differences have decreased with time with improvements in assays and laboratory testing practices. The educational component of both EQAS, which comprises workshops, laboratory questionnaires, consultancies, and newsletters, has had a critical impact on the testing practices of laboratories. Received: 30 October 2000 Accepted: 9 December 2000     

Advances in microbiology EQA

External quality assessment for microbiology laboratories has seen many changes over the past ten years. EQA is much less focused on the pure analytic process of identifying single organisms submitted in an artificial medium. Samples are more realistic, and can be used to address clinical relevancy. Samples can be supplemented with a variety of non-traditional challenges to extend testing to include a wider range of the pre- and post-analytic aspects of the laboratory cycle. A look to the future sees a broad range of newer targets, with increasing interest in virology and point-of-care testing. Received: 13 April 2002 Accepted: 24 June 2002     

Quality in clinical laboratory measurements

 Clinical chemistry deals with measurements and observations using samples from patients in order to supply clinicians with information to support their decisions in diagnosis and treatment. The discipline utilizes advanced chemical and biochemical methods and also sophisticated instrumentation which allows a high throughput. Clinical chemistry has a long tradition of quality assessment and improvement. The major tools have been proficiency testing or external quality assessment and internal quality control. Nowadays, total quality management has become widely recognized, and accreditation according to international, regional or national schemes has contributed to the design of quality systems and improvement of the reliability of results from clinical laboratories.     

Accreditation of PT providers – is it worth the money?

This topic is being presented from two perspectives, namely the views of an accreditation body and those of an accredited provider of external quality assessment schemes. The first perspective, from an accreditation body, is based on the experience of Australia's national laboratory accreditation body (NATA), which has accredited fourteen proficiency testing (PT) providers and is currently processing an application from another. The second perspective is based on the experience of EQUALIS, the national quality assurance organisation for laboratory medicine in Sweden, which was granted accreditation in 2002.Presented at 5^th Eurachem Workshop on Proficiency testing in analytical chemistry, microbiology and laboratory medicine, Portorož (Slovenia) 25–27 Sept 2005     

Proficiency testing in analytical chemistry, microbiology, and laboratory medicine – working group discussions on current status, problems, and future directions

Working group (WG) discussions on proficiency testing (PT) held at the joint Eurachem/ EQALM workshop, Borås, Sweden, 24–26 September 2000 are summarized. The discussions focused on aspects of PT and accreditation (WG 1), general aspects of PT in analytical chemistry (WG 2), microbiology (WG 3), and laboratory medicine (WG 4), incorporation of measurement uncertainty into PT schemes (WG 5), international harmonization of PT schemes (WG 6), and the role of PT in the international structure of chemical measurement (WG 7). Current status, problems and future directions are identified. Each WG contained a majority of participants experienced in the subject being covered by that WG, and a few participants with different expertise. This was done to promote cross-fertilization of ideas between sectors, a key objective of the workshop. The WG issues reflected the content of the keynote lectures and some issues were covered from different perspectives by more than one group.     

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.     

Proficiency testing in occupational and environmental health – Current practice and international initiatives for harmonisation

An increasing number of proficiency testing schemes (PT schemes) related to occupational and environmental health have been organised. Most schemes emphasise the importance of the validation of analytical results. With regards to harmonisation of the schemes, there are many differences between the schemes at many levels. These include factors concerning their relationship with legislation, national status, type and quality of proficiency testing material, analytical range and priorities for future development. Since differences between PT schemes have been recognised at the European level by organisers of PT schemes and external quality assessment schemes (EQASs) it seems appropriate to reinforce collaboration between scheme organisers in order to improve the quality of analytical performance in occupational and environmental health.     

An inter-laboratory comparison for determination of cortisol in saliva

An inter-laboratory comparison study for cortisol in saliva is reported in the present study. Nine laboratories representing four different methods participated in the study. Each laboratory measured five blind samples prepared from natural saliva spiked with a pure certified reference material in the range 0–70 nmol/L. The average observed values were established as means of eight laboratories, because one laboratory was excluded as an outlier. The natural content of cortisol in the pooled saliva was 6.8 nmol/L. The recovery of the certified reference material was 83%–131% (164% for the outlying laboratory). For five laboratories the 95%-confidence intervals of the recoveries did not cover 100%. The standard deviations for a concentration of 10 nmol/L were estimated for each laboratory. They were 0.64–1.67 nmol/L (6.26 nmol/L for the outlying laboratory). The present study emphasizes the need for an external proficiency-testing scheme and a certified reference material for cortisol in saliva. Received: 8 May 2002 Accepted: 3 September 2002     

Applications of Electron Microbeam Analysis in the Earth Sciences

 Naturally formed geological materials are not constrained in the number of elements which may be present and a wide range of concentrations can be expected. Oxides are a frequent component and water may be present. The particular problems posed for quantitative analysis in some representative applications are described and solutions suggested. Critical testing of the results for consistency with mineral formulae and for repeatability provides confidence in those results. Examples of applications of quantitative analysis of minerals are used to show the variety of problems encountered in electron microbeam analysis and how the analytical results can be used to determine the conditions (time, pressure, temperature) of the minerals or the rocks in which they occur.     

Study of the Fluorescence System of Europium–Enoxacin and its Applications

 This paper is the study of the fluorescence enhancement of Eu³⁺-1-ethyl-6-fluoro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridin-3-carbonic acid (enoxacin, EFLX) system by surfactants. It was found that sodium dodecylbenzenesulfonate (SDBS) exhibits great enhancement on the fluorescence of the Eu-EFLX system. The molar ratio is 1:2:1 for Eu:EFLX: SDBS. Under the optimum conditions, the fluorescence intensity is a linear function of europium in the range of 1.0 × 10⁻⁸ ∼ 5.0 × 10⁻⁶ mol/L, the detection limit is 1.0 × 10⁻⁹ mol/L. The application of the Eu-EFLX-SDBS system for the determination of trace europium in rare earth samples gave satisfactory results. Received October 19, 2000. Revision August 10, 2001.     

A practitioner's approach to the assessment of the quality of sampling, sample preparation, and subsampling

 The methodology of evaluating the performance of sampling, sample preparation, and subsampling is reviewed. The requirements to be set for a successful experiment are revisited. The central role of the reference method is explained, and so is the choice of the parameters and the measurement methods. Based on the principles of the "Guide to the expression of uncertainty in measurement" (GUM), a statistical model is developed that demonstrates the influence of the experimental design on the outcome of the assessment experiment. This relationship is often overlooked in practice, as it is hardly mentioned in written standards dealing with this kind of quality assessments. The statistical framework thus developed covers the statistical procedures commonly appearing in written standards. Finally, the issue of testing the significance of the bias obtained from the experiment is discussed. Received: 14 June 1997 · Accepted: 2 September 1997     

Requirements vs acceptability in proficiency testing schemes and other interlaboratory comparisons

Many laboratories take part in proficiency testing schemes, external quality assessment programmes and other interlaboratory comparisons. These have many similarities but also important differences in their modus operandi and evaluation of performance of participating laboratories. This paper attempts to highlight both the similarities and differences. It also puts particular emphasis on requirements called ”target values for uncertainty” and their meaning. Received: 24 January 2001 Accepted: 25 January 2001     

A dedicated External Quality Assessment system for immunoassays of reproductive hormones

A dedicated External Quality Assessment (EQA) system for immunoassays of reproductive hormones (LH, FSH, prolactin, hCG, progesterone, estradiol, testosterone) and cortisol was developed. This catered for the needs of a group of laboratories conducting collaborative research with the WHO in the field of human reproduction. This system was designed to provide the maximum information on assay quality with the final aim of achieving and maintaining the highest possible comparability in monitored multi-center clinical studies. The EQA was based on the assays of 32 control samples per year in 4 quarterly assay runs and the evaluation of the following parameters: bias, between-run imprecision within a laboratory, number of outliers, frequency of returned assays of control samples, and between-laboratory imprecision. The data obtained were combined in a performance index for each laboratory, EQA run, and analyte. This index was then subjected to ranking. It may be assumed that the EQA system contributed to improvements of analytical work and/or the maintenance of a high assay quality in participating laboratories. Received: 26 July 2001 Accepted: 9 November 2001