A latex agglutination test for detection of meningitis was approved. Calculate the sensitivity and specificity of the test based on the data given below: Test PositiveTest NegativeDiseased273Non-diseased595
Sensitivity 90% Specificity 95%
Specificity 90% Sensitivity 95%
Sensitivity 80% Specificity 90%
Sensitivity 75% Specificity 95%
Ans: A. Sensitivity 90% Specificity 95%Sensitivity:Introduced as a statistical index of diagnostic accuracy.Defined as the ability of a test to identify correctly all those who have the disease, that is 'true positive:"Specificity:Measures the propoion of negatives that are correctly identified as such, e.g., the percentage of healthy people who are correctly identified as not having the condition, that is true negative. Sensitivity = Propoion of persons with the condition who test positive: a /(a + c)`t = 27/30 = 90% .Specificity = Propoion of persons without the condition who test negative: d /(b + d)deg = 95/100 = 95%.