What is Sensitivity and Specificity?

Sensitivity and specificity are terms generally used by physicians, medical researchers, and epidemiologists. Currently, the mainstream media widely use these terms without a clear direction to help their audience understand what they are. What does it measure? How it affects our decision making capability regarding both personal and professional medical care?

This discipline of biostatistics helps determine the accuracy of medical tests. Think of it as testing the tests. So when you hear these terms, try to think of it from that concept. A more layman’s concept to think of like this. Imagine the doctor as a fisherman, and the test as the fishing net. A fisherman wants to use the best net possible to catch lionfish. Sensitivity and specificity are how we measure how useful that fishing net is. So let’s dive right into it. 

The sensitivity of a test is what it implies. It determines how SENSITIVE a test is regarding the disease of interest. So when you hear the sensitivity of a test is 80%, this is what that means. So going back to our fishing concept, the fishing net catches 80% of fish. 80% of what our fisherman consisted of were all different types of fish. The remaining 20% caught something other than fish like crabs, some seaweed, shrimp, octopus, a rock, or anything other than fish. So our fishing net is only 80% sensitive to fish, but our fisherman wants specifically lionfish. So now, let’s get specific. 

The specificity of a test is what it implies as well. It determines how SPECIFIC a test is regarding the disease of interest. So when you hear the specificity of a test is 10%, this is what it means. Again, back to our fishing concept, our fishing net is 10% specific to lionfish. Meaning our fishing net captured 90% of fish we didn’t want. So our fishing net is 80% sensitive and 10% specific, which is not precisely the best net to capture lionfish. 

COVID-19 is like our lionfish, and the tests we use to either diagnose or measure immunity, are our fishing net. The goal of every test is to be 100% sensitive and 100% specific; however, unfortunately, perfection never exists in nature, but we’ve developed tests that come close to it. The primary focus of Sensitivity and Specificity is to help guide and manage patient care to the best of our abilities.

The COVD-19 antibody tests available at LabFinder have over 90% Sensitivity and Specificity, which are one of the most accurate tests on the market regarding COVID-19.