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:\r\n \r\n\r\n\r\n\r\nMYOCARDIAL INFARCTION\r\n\r\n \r\n \r\n \r\n\r\n\r\n\r\nECG\r\n\r\n\r\nPRESENT\r\n\r\n\r\nABSENT\r\n\r\n\r\nTOTAL\r\n\r\n\r\n\r\n\r\nPOSITIVE\r\n\r\n\r\n416\r\n\r\n\r\n9\r\n\r\n\r\n425\r\n\r\n\r\n\r\n\r\nNEGATIVE\r\n\r\n\r\n104\r\n\r\n\r\n171\r\n\r\n\r\n275\r\n\r\n\r\n\r\n\r\nTOTAL\r\n\r\n\r\n520\r\n\r\n\r\n180\r\n\r\n\r\n700\r\n\r\n\r\n\r\n
Specificity=true negative/(true negative+ false positive) 171/180 x 100= 95% Ref: Medical biostatistics, 1st edition pg: 199
20%
55%
80%
95%