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Manufacturer declarations – pits and pitfals

In the modern clinical chemistry laboratory, almost all measurement procedures are done on different analytical platforms with ready-to- use reagents. In the everyday work we aim to choose the best reagents in order to obtain results that fulfil quality requirements proposed by professional organizations. The assurance of quality for the IVD reagents is CE marking that indicates conformity to the legal requirements of the European Union. Declaration sheets accompanying the reagents should therefore, be traceable to the established standards and provide all necessary data to their customers. Unfortunately, in the practise that is not always the case. Today, accreditation of laboratories according to standard ISO 15189 has become an imperative for quality assurance. According to the ISO standard, all relevant characteristics of a certain measurement procedure have to be known in order to assure optimal performances and minimize the risk of errors. According to the requirement 5.5.3. of the ISO 15189 standard, documentation of the measurement procedure should include, among other things, data on performance characteristics, calibration procedures, quality control procedures, interferences and cross reactions. Most of this data should be provided by the manufacturers of laboratory reagents in package inserts and data sheets. This is where the problems begin. Some declarations lack a large amount of data. Even when the data are presented, they are sometimes not adequate, certainly not standardized among different manufacturers and often not following required CLSI or any other guidelines. Let us review this on declarations for precision. Precision is one of the key performance characteristic of the test. Manufacturer has to declare data on precision to enable to the laboratory specialist to asses it the test will fulfil intended use. At first glance, all manufacturers’ declarations seem similar. They contain similar paragraphs and almost all include paragraph on precision. We have compared manufacturer’s declaration on precision for the 4 manufacturers available in our lab: manufacturer A (CE mark) declares data obtained by running QC samples on 3 concentration levels, without any specification of the time interval when the measurement is done. It is not clear if this is within-run or between run precision. Manufacturer B (no CE mark) declared within-run precision by running serum samples and between run precision by running QC sample, all on 3 levels. Manufacturer C (CE mark) declares data for within-run and between run precision on 2 levels, but it is unclear which samples were used (serum samples or QC samples). Manufacturer D (CE mark) states data obtained by running serum samples, on 3 concentration levels for both, within-run and between run precision. Even from this small studied sample it is clearly evident that there is a great heterogeneity between manufacturers in the way they are declaring precision of the test: materials used (serum or control samples), number of levels tested, time interval of the testing. It is imperative that the data provided by the manufacturers should be detailed, adhered to relevant guidelines, and standardized among different manufacturers. This is extremely important because it enables an educated comparison between different manufacturers when choosing the best available test for the implementation into everyday use. It is therefore our obligation as laboratory specialists to raise conciseness about this issue and force harmonization in this field.

IVD reagents; manufacturers declarations; harmonisation

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