Retrospective analysis of 55,769 HbA1c EQA results obtained from professional laboratories and medical offices participating in surveys organized by two European EQA centers over a nine-year period.

External Quality Assessment (EQA) is an essential tool for laboratories to monitor the performances of their analyses. It also allows a comparison of methods and types of laboratories (professional laboratories vs. medical offices). We, therefore, compared 55,769 HbA1c EQA results obtained between 1999 and 2008 by laboratories participating in EQA schemes organized by two European centers, Switzerland (center 1) and France (center 2). We used simple, nonparametrical statistics suited to EQA results to calculate the yearly and global precision performances. All the results, including the outliers, were included in the calculations. The best global precision performances were obtained by professional laboratories and medical offices using DCA POCT devices, followed by professional laboratories with the Integra, Hitachi, Cobas Mira, and HPLC groups of devices, and finally by both types of laboratories with the NycoCard POCT devices. When considering yearly precision performances, an overall improvement over time was observed for almost all diagnostic devices of center 1, whereas the trend was less clear for center 2. The HbA1c EQA results collected and analyzed over a 9-year period showed that the DCA POCT devices used either by professional laboratories or medical offices had better reproducibility than laboratory devices (other than POCT) and that a general improvement of yearly precision performances was observed, especially when frequent EQA schemes were organized.

Retrospective analysis of 88,429 serum and urine glucose EQA results obtained from professional laboratories and medical offices participating in surveys organized by three European EQA centers between 1996 and 2007.

BACKGROUND: The aim of this study was to provide inter-laboratory imprecision comparisons of different groups of diagnostic systems as well as a comparison of professional laboratories with medical offices performance on the basis of 88,429 glucose results obtained in external quality assessment (EQA) schemes organized by three European EQA centers between 1996 and 2007. METHODS: A simple, non-parametrical statistical model suited to all EQA results, including outliers, was used to calculate yearly and global performance. RESULTS: The best performance was obtained from professional laboratories with a group of three diagnostic systems--Hitachi, Integra, and Vitros, followed by Cobas Mira, and finally by Reflotron. For medical offices, the best performance was achieved with the Cobas Mira diagnostic systems, followed by the Reflotron, SpotChem, and Vitros DT60 diagnostic systems. A slight but overall improvement in performance over time was observed for most diagnostic devices. CONCLUSIONS: The analysis of glucose EQA results collected over a 12-year period showed that professional laboratories obtained better performances than medical offices, and that a general improvement in yearly performance was observed for both types of laboratories.

Quality assurance in road traffic analyses in Switzerland.

Swiss laboratories performing toxicological road traffic analyses have been authorized for many years by the Swiss Federal Roads Office (FEDRO). In 2003 FEDRO signed a contract with the Swiss Society of Legal Medicine (SSLM) to organize the complete quality management concerning road traffic analyses. For this purpose a multidisciplinary working group was established under the name of "road traffic commission (RTC)". RTC has to organize external quality control, to interpret the results of these controls, to perform audits in the laboratories and to report all results to FEDRO. Furthermore the working group can be mandated for special tasks by FEDRO. As an independent organization the Swiss Center for Quality Control (CSCQ) in Geneva manages the external quality controls in the laboratory over the past years. All tested drugs and psychoactive substances are listed in a federal instruction. The so-called 'zero tolerance substances' (THC, morphine, cocaine, amphetamine, methamphetamine, MDMA and MDEA) and their metabolites have to be tested once a year, all other substances (benzodiazepines, zolpidem, phenobarbital, etc.) periodically. Results over the last years show that all laboratories are generally within the confidence interval of +/-30% of the mean value. In cases of non-conformities measures have to be taken immediately and reported to the working group. External audits are performed triennially but accredited laboratories can combine this audit with the approval of the Swiss Accreditation Service (SAS). During the audits a special checklist filled in by the laboratory director is assessed. Non-conformities have to be corrected. During the process of establishing a new legislation, RTC had an opportunity of advising FEDRO. In collaboration with FEDRO, RTC and hence SSLM can work actively on improving of quality assurance in road traffic toxicological analyses, and has an opportunity to bring its professional requests to the federal authorities.

External quality control results of urine dip-slide devices.

Urinary tract infections are frequently diagnosed by using urine dip-slide devices, especially in medical practices and small laboratories. We performed a retrospective analysis of more than 3000 results obtained by several urine dip-slide devices during external quality control surveys. We found that an underestimation of bacterial counts and a difficulty in identifying mixed flora were relatively more frequent in medical practices than in specialized laboratories, and that regular participation in external quality control surveys correlates with better performances.

Guidelines for setting up an external quality assessment scheme for blood smear interpretation. Part II: survey preparation, statistical evaluation and reporting.

Blood smear analysis is a well-known technique in medical laboratories. The clinical relevance of this analysis and its interpretation are very important. Consequently, monitoring of laboratory performance by an external quality assessment scheme is strongly recommended. This article represents a very practical guidance document for External Quality Assessment Scheme (EQAS) organizers for setting up blood smear schemes. In the first part of the guidelines, the Hematology Working Group of the European External Committee for External Quality Assurance Programmes in Laboratory Medicine (EQALM) published practical information for the preparation of blood smears for use in an EQAS. Part II focuses on aspects such as survey preparation, statistical evaluation and reporting, and describes particular details for organizing blood morphology EQA surveys by means of virtual microscopy.

Frequently asked questions at the Quality Control Centre Switzerland (CSCQ).

The Quality Control Centre Switzerland (CSCQ) is one of two National EQAS organisers for the medical laboratory. Frequently asked questions at the CSCQ from two time periods have been analysed and compared. They form one of the sources for continuous improvement. It turns out that question frequency per se is not a criterion for the intended purpose. Well formulated single questions or remarks from different sources, together with the institutionalized practice of process evaluation, can lead to specific measures.