External Quality Assessment (EQA) of Randomly Blinded Rechecking Slides on TB AFB Microscopy Laboratories: A Retrospective Study, Addis Ababa, Ethiopia

Abstract

Tuberculosis (TB) is an infectious disease caused mainly by bacillus Mycobacterium tuberculosis and it remains a major public health problem. Globally, 9.6 Million people were ill and 1.5 million were died of Tuberculosis in 2014. In resource limited settings, tuberculosis diagnosis relies on sputum smear microscopy: with low and variable sensitivities, in adequately trained personnel, erratic reagent supplies, and poorly verified equipment. Thus there is a critical need for investment in laboratory capacity building and quality assured service. The objective of this study is to assess the performance and trend of Acid Fast Bacilli (AFB) smear microscopy external quality assessment program in Addis Ababa city Government. For this study a retrospective record review study was carried out among the participated AFB smear microscopy laboratories in Addis Ababa. The data was collected and summarized from 12 Jan. 2014 to March 20, 2015 in Addis Ababa Health research laboratory. The data entered in to EPI data V.3 and analyzed by SPSS version 20. Percentage of agreement for smear positive and negative results between periphery diagnostic health facilities and the regional laboratory was 95% and 99%, respectively. They have an observed agreement (Po) of 0.9918 and an expected agreement (Pe) of 0.8290. Moreover, Calculated kappa value was 0.95 which is almost perfect agreement. The trend of discordant slides decreases as participation in Regional External Quality Assurance System (REQAS) increases. This study concludes with evidences from the result that, Quality assured laboratory is the cornerstone for effective tuberculosis control programme. Continuous participation in REQAS and drilling of laboratory personnel accordingly at regular intervals plays an important role for improving the quality of TB laboratory services.