ECG was performed on a total of 700 subjects with complaints of acute chest pain. Of these, 520 patients had myocardial infarction. Calculate the specificity of ECG: MYOCARDIAL INFARCTION ECG PRESENT ABSENT TOTAL POSITIVE 416 9 425 NEGATIVE 104 171 275 TOTAL 520 180 700
Specificity=true negative/(true negative+ false positive) 171/180 x 100= 95% Ref: Medical biostatistics, 1st edition pg: 199
20%
55%
80%
95%