Case::
Case: 50M, COPD, Cough, sputum, mild fever. Wheezed throughout Reduced breath sounds, dull percussion note at right base, but NO egophony or increased vocal resonance.
CXR:
CXR
Test characteristics:
Test characteristics Target Disorder Present Absent Test Result Positive A B Negative C D Define Sensitivity: Define Specificity
Test characteristics:
Test characteristics Target Disorder Present Absent Test Result Positive A B Negative C D Define Sensitivity: A+A=C Define Specificity
Test characteristics:
Test characteristics Target Disorder Present Absent Test Result Positive A B Negative C D Define Sensitivity: A/A+C Define Specificity: D/B+D
Sensitivity and Specificity:
Sensitivity and Specificity Sensitivity: “Positivity in disease” Specificity: “Negativity in health” Sensitive tests are ALWAYS positive in disease Specific tests are ONLY positive in disease When negative, sensitive tests rule things OUT ( SnOUT ) When positive, specific tests rule things IN ( SpIN )
Egophony:
Egophony Sensitivity: 4-16%. Specificity: 96-99%. People with egophony ALWAYS have pneumonia. People with pneumonia SELDOM have egophony . Presence rules pneumonia IN. Absence does not rule it OUT. Steven McGee, Evidence-Based Physical Diagnosis