The Number Needed to Treat (NNT) is the number of patients you need to treat to prevent one additional bad outcome (death, stroke, etc.). For example, if a drug has an NNT of 5, it means you have to treat 5 people with the drug to prevent one additional bad outcome.
"The ratio of the risk of an event in the experimental group compared to that of the control group (RR=EER / CER). Not to be confused with relative risk reduction." --CEBM Glossary
A statistic that quantifies the strength of association between "events" and "non-events". --CEBM Glossary
"The likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that the same result would be expected in a patient without that disorder." --CEBM Glossary
"The range around a study’s result within which we would expect the true value to lie. CIs account for the sampling error between the study population and the wider population the study is supposed to represent." --CEBM Glossary
Sensitivity is The proportion of people with disease who have a positive test. While Specificity, is the proportion of people free of a disease who have a negative test.