Impact of international standards and initiatives on proficiency testing for medical laboratories

This paper is intended to briefly discuss several recent initiatives regarding External Quality Assessment (or Proficiency Testing) (PT/EQA) for medical laboratories in various parts of the world. While a brief paper cannot be comprehensive for all regions, it is possible to present some new standards and initiatives that are underway or proposed in many countries. Laboratory medicine was one of the first areas of laboratory testing to develop interlaboratory comparisons, and the first area where such comparisons became compulsory. Because of that, the medical field has often been the leader in the availability and use of PT/EQA, and has introduced many innovations that have been adopted in other areas. Perhaps other areas of testing will similarly adopt the developments discussed here, if they have not already done so. There are important developments in the medical area that are also occurring in other fields of testing, such as the growing number of countries that require some form of participation, and the increasing use of the Internet. These developments are important, but are not discussed further in this paper since they are occurring in many fields of testing.     

Proficiency testing in analytical chemistry, microbiology and laboratory medicine: working discussions on current practice and future directions

A summary of the working group (WG) discussions on proficiency testing (PT) and external quality assessment (EQA) held at the Eurachem Workshop, Rome, 5–7 October 2008 is provided. The eight WG’s covered a range of issues concerned with current practice and future directions; how frequently should laboratories participate in PT/EQA? (WG1); developments in PT/EQA within the EU—what is required in future? (WG2); what issues do developing countries face with regards to PT/EQA? (WG3), what issues are specific to microbiology PT/EQA? (WG4); what new fields are emerging for PT/EQA? (WG5); what will be the impact of the new ISO/IEC 17043 standard? (WG6); do current PT/EQA schemes meet the needs of participants? (WG7); and what are the issues that affect the quality of proficiency test items? (WG8). Delegates with different backgrounds were on each WG in order to capture a range of views and experience from a number of different sectors. Working group representatives included PT/EQA providers, participants in PT/EQA schemes and end users of PT results such as accreditation bodies and regulatory authorities, from countries around the world.     

Proficiency testing in analytical chemistry, microbiology and laboratory medicine: working discussions on current practice and future directions

A summary of the working group (WG) discussions on proficiency testing (PT) and external quality assessment (EQA) held at the EURACHEM Workshop, Istanbul, 3?C6 October 2011, is provided. The six WGs covered a range of issues concerned with current practice and future directions; implementing the requirements of ISO/IEC 17043 by PT/EQA providers (WG1); accrediting PT/EQA providers to ISO/IEC 17043 (WG2); pre- and post-analytical aspects in PT/EQA (WG3); evaluating participant performance in qualitative PT/EQA schemes (WG4); establishing PT/EQA schemes in developing countries (WG5); and establishing acceptability criteria in microbiology PT/EQA schemes (WG6). Delegates with different backgrounds were on each WG in order to capture a range of views and experience from a number of different sectors. Working group representatives included PT/EQA providers, participants in PT/EQA schemes and end-users of PT results such as accreditation bodies and regulatory authorities, from countries around the world.     

Surveys on the accreditation of providers of proficiency testing and external quality assessment schemes

Two surveys among providers of proficiency testing (PT) and external quality assessment (EQA) schemes were carried out during 2004 and 2005. The main objectives were to explore the current status of accreditation/certification and collect the providers’ views. Information based on the response from 160 providers in 32 countries reveals a strong tendency towards accreditation of PT/EQA. It is shown that this type of accreditation is based on several combinations of normative documents, hence illustrating a lack of harmonisation of national accreditation bodies. The surveys also show that schemes are operated under considerably different conditions and that providers’ competence may or may not be underpinned by other certification and/or accreditation. This paper elaborates on a number of issues related to PT/EQA accreditation, including customers’ views, normative documents, providers’ experience from the accreditation process, views expressed by international organisations, and effects of accreditation on participation fees, quality and availability.     

Proficiency testing in analytical chemistry, microbiology and laboratory medicine: working group discussions on current practice and future directions

A summary of the working group (WG) discussions on proficiency testing (PT) and external quality assessment (EQA) held at the joint EURACHEM/CITAC/EQALM workshop, Bracknell, UK, 16–18 February 2003 is provided. The nine WGs covered a range of issues concerned with current practice and future directions; PT/EQA as a tool for regulators (WG1); PT/EQA as a tool for accreditation (WG2); evaluation of performance and uncertainty (WG3); frequency of PT/EQA participation (WG4); selection of appropriate PT/EQA schemes (WG5); added value of PT/EQA and cost benefit evaluation (WG6); global harmonisation and rationalisation (WG7); new technical areas and challenges in PT/EQA (WG8); and accreditation of PT/EQA providers (WG9). Participants with different backgrounds were on each WG in order to capture a range of views and experience from different sectors. The discussions reflected on the keynote lectures and built, in many cases, on discussions at previous workshops in 2000 and 2002.     

Policies,requirements and surveys concerning frequency for participation in proficiency testing schemes

This paper focuses on policies and requirements concerning the frequency for participation in proficiency testing (PT) and provides an overview of the frequency for which PT activities are offered in 25 testing fields. Recent international surveys are summarised.

     

Proficiency testing in analytical chemistry,microbiology and laboratory medicine: discussions on current practice and future directions

Accreditation and Quality Assurance - A summary of the working group discussions on proficiency testing (PT) and external quality assessment (EQA) held at the Eurachem Workshop, Portorož,...     

Use of participant EQA results to assess sample homogeneity and stability for qualitative analytes

International requirements for PT and EQA state that providers must demonstrate that samples are homogeneous and stable. However, testing for homogeneity and stability can be expensive, use samples that could otherwise serve as quality-control materials, and can also fail to detect significant inhomogeneity and instability. In some situations it may be preferable to use the results from participants to identify problems with sample lots, if historic results follow predictable distributions and a statistical decision rule can be produced. An unusually high proportion of incorrect results may indicate that samples were inhomogeneous or unstable. Conditions under which this can be demonstrated are discussed, and the efficacy of the proposal is demonstrated with two examples. This procedure is especially effective when there are a large number of participants and/or a historic small proportion of incorrect results. Providers who adopt this proposal will need to retain samples for testing and assume the risk of distributing bad samples.Presented at the Eurachem PT Workshop September 2005, Portorož, Slovenia     

Harmonisation of proficiency testing schemes

The harmonisation of proficiency testing (PT) schemes has been under debate for a long time. There are obvious reasons why harmonisation of the practices in PT would be beneficial. In many areas, there is still a belief that further harmonisation of practices in PT would improve the comparability of measurement data. In particular when two laboratories are to be compared that have not participated in a single PT, problems arise which allegedly can be overcome by further harmonisation of PT schemes. In practice, however, parties involved in PT are not always embracing the idea of harmonisation. With the results of two European projects in mind, a discussion is given on harmonisation aspects, and some considerations are given that may help to decide in practice whether harmonisation is likely to solve particular problems. The first project, the European Proficiency Testing Network (EPTN), is concerned with further harmonisation. The second European project (COEPT) aims at providing a basis to assess equivalence across proficiency tests, and explores the conditions under which such an assessment is feasible.

     

Do we need to accredit proficiency testing schemes?

 Proficiency testing (PT) is being increasingly used as an important quality assurance tool for laboratories. The subject of quality of the providers of PT schemes has been discussed increasingly in recent years. Some countries have implemented systems for the accreditation of PT schemes. This paper looks at the background to the accreditation of PT schemes, the likely mechanisms which could be employed for accreditation, and some of the practical aspects.     

Policies, requirements and surveys concerning frequency for participation in proficiency testing schemes

This paper focuses on policies and requirements concerning the frequency for participation in proficiency testing (PT) and provides an overview of the frequency for which PT activities are offered in 25 testing fields. Recent international surveys are summarised.     

Evaluating participant performance in qualitative PT/EQA schemes

A basic principle that needs to be satisfied before a proficiency testing (PT)/external quality assessment (EQA) scheme is first introduced is that measurement and assessment of performance is possible. For qualitative analyses, data can be presented as ??percentage correct??, and these data can be aggregated to show trends and to facilitate monitoring performance over time. Alternatively data can be analysed to identify significant patterns or changes in practice, or to compare different categories. However, the most useful tool is the application of a numerical score to the results. A number of different scoring strategies can be used, varying in complexity depending on the nature and significance of the type of results generated. Examples from selected microbiological EQA schemes are presented.     

Low-CD4+ T-lymphocyte blood samples for external quality assessment of CD4 testing in resource-poor settings

External quality assessment (EQA) of CD4 testing is important for clinically monitoring of patients with HIV/AIDS. EQA materials are limited to blood samples from normal blood donors with normal CD4+ T-lymphocyte levels. This study aimed to develop low-CD4+ T-lymphocyte blood samples for CD4 EQA. CD4+ T-lymphocyte-depleted blood samples were prepared using a magnetic bead separation technique. These CD4+ T-lymphocyte-depleted blood samples were mixed with undepleted whole blood samples to obtain low-CD4+ T-lymphocyte blood samples. The percentage and the number of CD4+ T-lymphocytes were determined using a flow cytometer. An evaluation study of this low-CD4+ T-lymphocyte blood sample was performed by sending to participating laboratories to investigate the potential use as CD4 EQA material. Our results showed that a magnetic separation technique could be used to prepare low-CD4+ T-lymphocyte blood samples. CD4+ T-lymphocytes in the low-CD4+ T-lymphocyte blood samples ranged from 15 % to 18 % and 160–300 cell/μl, respectively. In addition, CD4 testing of our low-CD4+ T-lymphocyte blood samples could be achieved following both the single- and the dual-platform flow cytometric approaches. A pilot EQA investigation revealed that the CV values of the number and percentage of CD4+ T-lymphocytes were 14 % and 10 %, respectively. Having the low-CD4+ T-lymphocyte blood samples in our CD4 EQA program should ensure reliability and credibility of CD4 testing in Thailand and other resource-poor countries.     

Food irradiation: regulatory aspects in the Asia and Pacific region

Irradiation treatment of food is becoming an increasingly accepted processing option for countries in the Asia Pacific region wishing to meet growing sanitary and phytosanitary requirements in international trade. There remain however, large differences between the regulatory requirements in the countries in this region.

This paper gives an outline on existing food irradiation regulations in the separate countries of the Asia Pacific region. New developments such as the recent decision by the Australia New Zealand Food Authority to start assessing applications for food irradiation treatment are discussed. Australia's intention to regulate the export of food treated by irradiation will also be outlined.

Details of the decision to harmonise food irradiation regulations by 13 countries in the Asia Pacific region based on conformance with Codex requirements is outlined. The likelihood of other Asia Pacific countries enacting similar harmonisation of their regulations will be examined. Future development such as certification of irradiation as a sanitary treatment for food are discussed. The expected result of these initiatives is a likely increase in irradiated foods traded within the Asia Pacific region.     

Proficiency testing schemes for therapeutics and toxicology

 This report addresses the proposition: current proficiency testing (PT) schemes for therapeutics and toxicology can easily engender complacency. The proposition was based on the premise that there are substantial between-laboratory differences and objectives in the supply of services for the measurement of drugs, as a result of which it is difficult to design PT schemes which adequately cover the requirements of all laboratories. Thus, acceptable performance in a PT scheme may lead participants to consider that they have tested their procedures more rigorously than is the case. Four areas, validity of the PT scheme, PT material, frequency of testing and acceptance criteria are examined. Received: 15 April 2000 · Accepted: 15 April 2000     

Experience with in-house PT-schemes in the chemical industry

There are many different means of demonstrating the quality of performance of an analytical laboratory. Proficiency testing (PT) is just one! As in other analytical fields, interlaboratory comparisons play an important role in the chemical industry. Collaborative trials or method performance studies do have a long tradition in this field. Sometimes they were designed as laboratory performance studies with the clear aim of making analytical results comparable, e.g. petrol, coal, gas, noble metals analyses – not to mention the biggest PT scheme run on a daily world-wide basis – trade itself. All this is an ongoing process, which started long before the idea of assessing and accrediting the performance of analytical laboratories was born. However, when striving for accreditation in 1996, the analytical production laboratories of the Chemicals Business Unit of the Bayer AG in Germany implemented another facet of PT schemes. In-house-PT schemes are performed regularly and turned out to be useful in evaluating, monitoring, and thus improving, the quality of routine analytical work. Received: 5 December 2000 Accepted: 15 January 2001     

Uses and abuses of PT

Proficiency testing (PT) is a very valuable quality tool for laboratories making all kinds of analytical measurements, in chemistry, microbiology and laboratory medicine. Compared with other quality tools, which are largely concerned with INPUTS (e.g. staff training, calibration, documentation), PT is concerned with OUTPUTS (i.e. the actual results produced by the laboratory). The quality of routine measurements and results, which would normally be reported to customers, both internal and external, should be demonstrated. This is a major reason for many laboratories participating in PT, even if they are not accredited, or use very few, if any, other quality tools. This is important, for it enables the laboratory manager to measure the efficacy of the overall quality system, and to determine if the inputs to this are appropriate. This should be done in a spirit of learning—it was discussed at the previous workshop whether PT schemes are teachers or policemen, and the consensus was that MOST are teachers (or at least try to be). Learning from mistakes, investigating problems, implementing corrective actions and then observing whether thisis successful in the next PT represents what many in our profession would regard as a proper and effective use of PT. Although this may be the intended primary use of PT by laboratories, we must not forget that PT has other valid uses. In particular, the use of PT to demonstrate competence to third parties—accreditation bodies, regulators, and customers—has become more important in the last few years. However, this development, however valuable, can lead to abuse of PT scheme data. This paper will highlight briefly some examples of both proper use and abuse of PT. These are taken from my experience with PT schemes over many years.     

Bioterrorism: impact on external quality assessment service delivery

Safety issues related to the design, production and distribution of simulated specimens for microbiology external quality assessment (EQA) have occupied scheme organisers for many years. Since the anthrax attacks in Washington, USA in October 2001, there has been heightened awareness in the public domain regarding the transport of infectious substances. For instance, in direct response to the anthrax incident in the US, microbiology institutes in the UK that handle dangerous pathogens (like the Health Protection Agency) are registered with the national police force and are inspected regularly to ensure compliance with current legislation covering the control of these pathogens. The fear of a complete ban on the movement of infectious substances following the anthrax incident has not yet been realised, but remains a serious risk. Many countries such as the UK, USA, and Australia have introduced measures for the control, transportation, and health and safety aspects of handling and distribution of infectious materials. The national postal services of many countries do not accept infectious materials by mail. There are a limited number of courier services willing to transport dangerous goods, especially division 6.2 (infectious substances) and these services are costly. Measures can be implemented by scheme organisers to ensure best practice; for instance, by having sufficient and trained staff, with knowledge, expertise and use of computerised systems in the shipping/export department. Ensuring compliance with national and international health and safety legislation by providing safety data sheets and by carrying out product risk assessments is required to ensure transparency and to demonstrate duty of care. Organisers of microbiology EQA face uncertainty about the future survival of schemes in the current climate. It is imperative that practices and procedures are put into place that meet with the legislation and enable us to continue to support quality in laboratory medicine.

     

Environmental analysis in the Czech Republic: organisation of proficiency testing and its use in laboratory assessment

The history, origin, and development of a system for monitoring and assessing water and other environmental laboratories in the Czech Republic is described. The system started in 1991 and has matured to its present complexity with similarities to the accreditation systems found in other countries. Differences from internationally recognized procedures are being corrected step by step. During the first year of its existence ASLAB, as part of its brief, organised proficiency testing (PT) programs for fifty laboratories. Today the total number of regularly participating laboratories exceeds 700 from the Czech Republic, the Slovak Republic, and Germany. This paper describes the ASLAB PT system, discusses some experiences with its use, and describes the use of PT results in assessment of the competence of laboratories. Received: 12 October 2000 Accepted: 7 January 2001     

Twenty years of the Me.Tos. Project: an Italian national external quality assessment scheme for trace elements in biological fluids

The Me.Tos. Project, started in 1983 and still running, is an external quality assessment (EQA) scheme for laboratories performing specialized analyses in occupational and environmental laboratory medicine. Besides the organization of EQA exercises, initiatives for further education of the participants and the harmonization of EQA procedures at a European level are carried out. Participation in EQA schemes allows laboratories to comply with the international standards for the quality and competence of testing and clinical laboratories. The organization of the scheme includes the preparation of control materials, their distribution to the participants, according to strategies aimed to avoid identification of the samples, the statistical analysis of the results and the evaluation of laboratories' performance according to international guidelines and criteria set by the organizers. An overview of the scheme operation and the current performances of participants will be given.