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

Head-to-Head Trial

A study of two drugs or treatments that compares the effects of one treatment with the other. In a head-to-head trial, two groups of people with the same disease are compared. One group receives one treatment, and the second group receives the other. detail

Health Care Intervention

Any type of treatment, preventive care, or test that a person could take or undergo to improve health or to help with a particular problem. Health care interventions include drugs (either prescription drugs or drugs that can be bought without a prescription), foods, supplements (such as vitamins), vaccinations, screening tests (to rule out a certain disease), exercises (to improve fitness), hospital treatment, and certain kinds of care (such as physical therapy). detail

Heterogeneity

Differences among research studies. Heterogeneity can apply to either the way the studies were conducted, the methodologies used in the studies, or differences in the way people respond to the treatment. Research reports may describe different types of heterogeneity: detail

Human Subject

A person who participates in a research study or clinical trial. The person agrees to take part in the study and has been told about the possible dangers and benefits of participation. The participation can include different activities, depending on the goals of the study. detail

Hypothesis

A scientific idea that can be tested in a research study. The hypothesis is the scientific idea that led to the research study. detail