Avaliação externa da qualidade das baciloscopias para tuberculose, realizadas nas unidades laboratoriais públicas no município de Belém (Pará)

Abstract

The sputum examination is the most widely used for diagnosis and control of tuberculosis (TB), as a method of simple execution, low cost, but has low sensitivity and specificity. For the effectiveness and efficiency of this method are met, it is necessary for the establishment and application of standard rules of execution and reading of slides. Thus, it is essential to know the quality of smear microscopy available in a laboratory network. The aim of this study was to evaluate the quality of sputum for diagnosis and control of TB conducted in Units Laboratory (UL) belonging to the public laboratories in Belém, Pará, in 2007, 2008 and 2009. The evaluation was divided into three stages, corresponding to the year of manufacture of the sputum blades. Participants UL 18 that sent regularly to the Central Laboratory of Para, all smear slides prepared by them for External Quality Assessment of Smear (AEQB), which uses the method of blind rereading of smears. This method involves a technical evaluation of the smears, describing them as "Adequate" and "Inappropriate", besides the analysis of discrepant results False Positive (FP) and false negative (FN). During the study period, 4117 samples were processed by UL. In the first stage of evaluation, all 18 UL had blades that were classified as inadequate, and this number decreased to 12 UL in the 2nd stage of evaluation and UL for six at the 3rd step. Regarding disagreements, disagreements had 03 UL 03 UL FP and FN. The results obtained in this study reinforce the need to maintain and expand AEQB for all UL performing smear in the network of laboratories.