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
Increased sensitivity and positive predictive value
Increased sensitivity and negative predictive value
Increased specificity and positive predictive value
Increased specificity and negative predictive value