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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.

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Prevalence

Definition: How often or how frequently a disease or condition occurs in a group of people. Prevalence is calculated by dividing the number of people who have the disease or condition by the total number of people in the group.

Example: For example, health leaders in a community were concerned that some women were not receiving health care and therefore did not know they had serious problems. The health leaders began a breast cancer screening program. Women were encouraged to come into a community clinic and have breast examinations. In this example, out of 1,000 women, 20 had breast cancer. Therefore, the prevalence of breast cancer in women who undergo screening for breast cancer is 20/1000, or 2 percent.

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