Martínez RMR, García LG, Sardiña AM, Díaz AM, Columbie V, Pequero R, González OE, Montoro CE

Language: Spanish
References: 21
Page: 99-106
PDF size: 90.31 Kb.

ABSTRACT

Background: Quality control of smears for acid fast bacilli (AFB) is essential for the correct function of the specialized laboratory.
Objective: To evaluate two new methods for quality control of sputum smears for AFB in Cuba.
Method: Between January 2004 and December 2006, 2,058 smears were evaluated, 1,518 by the blinded rechecking method and 540 by the panel testing method. Selected laboratories from Havana City and Las Tunas provinces participated. Rechecking was applied quarterly and two controls were done, the first at the Provincial Laboratories of Microbiology of the participating counties and the second at the National Reference Laboratory (NRL), Institute Pedro Kouri. The panels were prepared and validated at the NRL before their twice a year application.
Results: With the rechecking method, we identified 4 reading errors during the first control, and 33 in the second. The general rate of errors, the rates of false positives and false negatives were not over 5% in the two controls carried out. The quality indicators showed values over 99%, with a kappa index of 0.9926 (p › 0.05). With the panel testing method 63 reading errors were detected.
Conclusions: By the blinded rechecking method, the agreement obtained between the two laboratories was high and the quality indicators showed acceptable values. The application of the panels testing allowed identification of the laboratories where the personnel needed additional training in order to improve their reading quality for AFB.

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