Sensitivity and specificity. Sensitivity and specificity are concepts used to assess a clinical test. Sensitivity is a measure that determines the ability of a test to correctly classify an individual as sick or diseased. Specificity is a measure of the ability of a test to correctly classify an individual as healthy or disease-free. Parikh and others reckons that sensitivity and specificity are inversely proportional, which means that as the value of sensitivity increases, the value of specificity decreases and vice versa.