Biomedical subjects

M J Castiñeiras-Lacambra

Publications and source records attributed to M J Castiñeiras-Lacambra.

3 recordsLinked to original sources

PubMed1999

Pre-metrological (pre-analytical) variation of some biochemical quantities.

It is customary to assume that pre-metrological variation is negligible if all pre-metrological sources of variation have been standardised. The aim of this study was to quantify the pre-metrological variation of some biochemical quantities frequently measured in clinical laboratories. The experimental design considers the different sources of pre-metrological variation that usually act day-to-day on samples from patients. The results demonstrate that, for many quantities, the pre-metrological variance is not negligible; consequently, it is suggested that these variances should be taken into account when estimating the uncertainty of measurement of patients' results.

Clinical Chemistry Tests↗

PubMed1997

Evaluation of the VALAB expert system.

The validation of a clinical laboratory report is a process that guarantees the results contained in the report have been obtained under satisfactory metrological conditions and that they are compatible with the information available on the patient. This validation is generally carried out manually by a clinical laboratory professional, but also may be done by an expert system properly programmed, such as the VALAB system. The evaluation presented in this article consists of comparing human and system decisions of validation for 500 randomly selected clinical laboratory reports from hospitalized patients. In this evaluation, 84.8% of the reports examined by the VALAB are accepted directly without any human aid, and only 15.2% require examination by clinical biochemists.

Clinical Chemistry Tests↗

PubMed1997

Multicentric reference values: shared reference limits.

In order to obtain shared reference limits, three laboratories in the same geographical area with a homogeneous population have developed a proposal to produce multicentric reference values. The strategy simulates a virtual laboratory, actually formed by the laboratories involved; the reference limits produced in the virtual laboratory are in fact derived from the blend of reference values obtained by each laboratory. Each laboratory has chosen its own reference sample and has measured the biochemical quantities under study. Reference individuals (n = 171) and 15 biochemical quantities among the most measured in clinical laboratories were selected. The reference values obtained in each laboratory were blended when permitted by the Harris & Boyd test (Clin Chem 1990; 36:265-70). The multicentric reference limits obtained by the virtual laboratory for each quantity were estimated according to the recommendations of the International Federation of Clinical Chemistry. For each quantity, each laboratory, with the results observed in their reference sample, estimated the diagnostic specificity, using as cut-off values the corresponding multicentric reference limits. Each observed value of diagnostic specificity was compared with the theoretical diagnostic specificity value, equal to 0.975, that should be observed when a reference limit is used as cut-off value. The multicentric reference limits obtained by the virtual laboratory are valid in all cases with the exception of the upper reference limit for the concentrations of calcium(II) and urate in serum in one of the laboratories.

Adult↗