Time to address quality control processes applied to antibody testing for infectious diseases.

As testing for infectious diseases moves from manual, biological testing such as complement fixation to high throughput automated autoanalyzer, the methods for controlling these assays have also changed to reflect those used in clinical chemistry. However, there are many differences between infectious disease serology and clinical chemistry testing, and these differences have not been considered when applying traditional quality control methods to serology. Infectious disease serology, which is highly regulated, detects antibodies of varying classes and to multiple and different antigens that change according to the organisms' genotype/serotype and stage of disease. Although the tests report a numerical value (usually signal to cut-off), they are not measuring an amount of antibodies, but the intensity of binding within the test system. All serology assays experience lot-to-lot variation, making the use of quality control methods used in clinical chemistry inappropriate. In many jurisdictions, the use of the manufacturer-provided kit controls is mandatory to validate the test run. Use of third-party controls, which are highly recommended by ISO 15189 and the World Health Organization, must be manufactured in a manner whereby they have minimal lot-to-lot variation and at a level where they detect exceptional variation. This paper outlines the differences between clinical chemistry and infectious disease serology and offers a range of recommendations when addressing the quality control of infectious disease serology.

Calibration - an under-appreciated component in the analytical process of the medical laboratories.

Calibration of an analytical measurement procedure is an important basis for the reliability of patient results. Many publications and as well as procedures on how to estimate quality control and interpret those results have been become available over the years. In this publication we are focusing on the critical part of the calibration as there are no clear communication or guidelines on how to perform it. Usually only the recommendation of the reagent or instrument manufacturer is available. We would like to point out this gap to invite for a discussion and improvement of the current situation.

Collective opinion paper on findings of the 2011 convocation of experts on laboratory quality.

In April of 2011, Bio-Rad Laboratories Quality System Division (Irvine, CA, USA) hosted its third annual convocation of experts on laboratory quality in the city of Salzburg, Austria. As in the past 2 years, over 60 experts from across Europe, Israel, USA and South Africa convened to discuss contemporary issues and topics of importance to the clinical laboratory. This year's conference had EN/ISO 15189 and accreditation as the common thread for most discussions, with topics ranging from how to meet requirements like uncertainty to knowledge gained from those already accredited. The participants were divided into five discussion working groups (WG) with assigned topics. The outcome of these discussions is the subject of this summary.

Monitoring quality indicators in laboratory medicine does not automatically result in quality improvement.

BACKGROUND: Data on quality indicators (QIs) should be collected over time in order to identify and continuously monitor clinical laboratory performance and to improve patient safety by identifying and implementing effective interventions. The aim of the present study was to ascertain whether the utilization of a set of quality indicators over a 3-year period resulted in an improvement in the efficiency and effectiveness of an individual laboratory. METHODS: Over a 3-year time interval (2009-2011), a series of 38 QIs covering all stages of the total testing process (21 in the pre-analytic, nine in the analytic and eight in the post-analytic phase) was monitored. RESULTS: On the basis of their patterns, QIs have been grouped into the following categories: [1] seven QIs of the pre-analytical phase and three of the intra-analytical phase with a significant trend and a significant linearity demonstrating an improvement over time; [2] 10 QIs of the pre-analytical and two of the intra-analytical phase with a significant trend and a non-significant linearity demonstrating that changes were not constant; [3] two QIs of the pre-analytical and one of the intra-analytical phase with a non-significant trend and significant linearity showing neither improvement nor worsening; and [4] two QIs of the pre-analytical and three of the intra-analytical phase with a non-significant trend and non-significant linearity. CONCLUSIONS: Data on a set of QIs collected over a 3-year time-frame demonstrate that processes and indicators under the control of the clinical laboratory had improved much more than processes requiring close co-operation between the laboratory and care teams.

Evaluation of the VITROS 5,1 FS chemistry system in a large pediatric laboratory.

The VITROS 5,1 FS analytical system was evaluated. The measurement of the serum proteins and HDL cholesterol with the newly developed MicroTip technology was compared with other nephelometric and turbidimetric methods. The within-run imprecision for apolipoprotein A1, apolipoprotein B, complement 3, complement 4, transferrin, immunoglobulin A, immunoglobulin M, immunoglobulin G and HDL cholesterol showed coefficients of variation between 0.4% and 4.7%. The day-to-day imprecision showed coefficients of variation between 0.5% and 4.0%. The correlation with the comparative methods (nephelometric or turbidimetric) was good, with Pearson correlation coefficients of between 0.959 and 0.995. The comparison of apolipoprotein Al showed a slope of about 0.76. An explanation for the difference could not be found. The VITROS 5,1 FS analytical system is a reliable routine instrument which fits into a large pediatric laboratory of a university.

Analytical interferences and analytical quality.

In today's health care system the prevalence of medical errors is high as stated by the report of the Institute of Medicine. A varying error rate of <10% in clinical medical laboratories has been reported in the literature. Most of these errors occur in the pre-analytical phase. Only a small number of errors will be seen in the analytical phase. This overview will deal with the analytical interferences and will offer ways to improve the analytical quality. Some special areas of the analytical process like calibration, quality control, reference interval, drug interference, statistical analysis and volume displacement will be covered. With some examples from the literature and own investigations the impact of errors in these steps of the analytical process will be better understood and the examples will help reducing the number of analytical errors and interferences. This finally provides better patient safety.