- Glossary of Terms
Glossary of Terms
We know that many of the concepts used on this site can be difficult to understand. For that reason, we have provided you with a glossary to help you make sense of the terms used in Comparative Effectiveness Research. Every word that is defined in this glossary should appear highlighted throughout the Web site. When you come upon a highlighted term and would like to read the full definition, you can either click on the word to visit the glossary or roll your mouse over the word for a pop-up definition.
- Positive Predictive Value
Definition: Indicates the likelihood that a person with a positive test result would actually have the condition for which the test is used. The higher the value of the positive predictive value (for example, 90 percent would be considered a high value), the more useful the test is for predicting that the person has the condition.
For example, the positive predictive value (PV+) of mammography in breast cancer screening has been estimated to be less than 30 percent. For every 100 people who have something discovered on their mammogram that looks like cancer, it will turn out actually to be cancer in less than 30 of those people.