ELISA is performed on a population with low prevalence. What would be the result of performing double screening ELISA tests?
ELISA is an extremely good screening test with a high sensitivity of over 99.5% but low specificity. The specificity of the technique is increased by carrying out ELISA tests in a row using different HIV marker. Predictive value depends on sensitivity, specificity and the positive predictive value. Thus double ELISA increases the specificity and the positive predictive value. Ref:A.P.I Textbook of Medicine, 6th Edition, Page 135