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ELISA BETTER THAN WE THOUGHT. Dr Direk Limmathurotsakul, MD MSc PhD. Introduction: problems and solutions of imperfect Gold Standard. Introduction: culture is an imperfect gold standard for melioidosis. Introduction: culture is an imperfect gold standard for melioidosis.
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ELISA BETTER THAN WE THOUGHT Dr Direk Limmathurotsakul, MD MSc PhD
Introduction: problems and solutions of imperfect Gold Standard
Introduction: culture is an imperfect gold standard for melioidosis
Introduction: culture is an imperfect gold standard for melioidosis Limmathurotsakul et al (2010) PLoS ONE 5(8) e12485
Next Step: What is the proper cutoff for ELISA • LCM estimate that true Se and Sp of ELISA were 76% and 98% • Cut-off used was previously determined by conventional ROC
METHOD • Bayesian latent class models (LCM) were applied to all possible cut-off values • Sensitivity and specificity estimated from each cut-off value was used to plot unbiased ROC curves
SUMMARY • Cut-off determined by conventional method was biased towards misclassification of imperfect gold standard • LCMs should be used to determine optimal cut-off • ELISA could be furthered developed for use in the clinical setting with a reasonably high degree of accuracy • Further evaluation of new diagnostic tests for melioidosis should be done with a carefully selected set of diagnostic tests and appropriate statistical models
How can general researchers apply Bayesian LCM to their own datasets http://mice.tropmedres.ac More information: PPI-37 (WMC2013)