Memorias del Instituto de Investigaciones en Ciencias de la Salud
versão On-line ISSN 1812-9528
RODRIGUEZ, E et al. External quality assessment in the determination of the uric acid in a group of clinical laboratories from Mérida-Venezuela. Mem. Inst. Investig. Cienc. Salud [online]. 2006, vol.4, n.1, pp. 28-33. ISSN 1812-9528.
The programs of external quality assessment began in Venezuela on 1977 for glucose, urea and creatinine, showing carelessness in the quality of the analyses. Being important to survey the analytical performance in this area, this work was developed to evaluate the performance in uric acid determinations of a group of clinical laboratories from Mérida (Venezuela). Commercial control sera: Normal Control (CN: 5.1 mg/dL) and Abnormal Control (CA: 9.7 mg/dL) were randomly distributed every fifteen days to 14 clinical laboratories (both public and private). They were asked to perform three determinations on each control serum, using the uricase-peroxidase method. The intra-laboratory and inter-laboratory precisions were determined through the variation coefficient (CV) and the intra-and inter-assay accuracies were determined through the percent relative deviation (DRP) of the individual value (intra-assay) or the mean of the three determinations (inter-assay) in relation to the consensus value. The lowest imprecision was obtained when performing the second determination of CA (CV=9.75%), 42.9% of the laboratories showed intra-laboratory precision (CV lower or equal than 5%) and inter-assay accuracy (DRP lower or equal than 15%) on both control sera. Further, 50% of the laboratories were accurate in the three CA determinations whereas 57.14% were accurate determining CN. The best performance was obtained in the second determination of CN and CA: 78.57% of the laboratories exhibited acceptable DRP values for CN and 85.71% for CA. We concluded that it is necessary to improve the reliability of the uric acid determination in these laboratories.
Palavras-chave : Consensus value; reliability; accuracy; precision.