- 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.
- Pooled Odds Ratio
Definition: When the data on odds ratios from multiple studies are combined, the result is a pooled odds ratio (POR). An odds ratio (OR) is the comparison of the chance of an event occurring in one group to the chance of it occurring in another group. The odds ratio is a measure of effect size and is commonly used to compare results in clinical trials.
Example: For example, researchers looked at the results of five different studies that compared using a particular drug for treating depression with using a placebo (inactive substance) to treat depression. They looked at the amount of weight gain in the people taking the drug compared to the people taking a placebo. When they calculated the odds of weight gain from each of the studies, the pooled odds ratio (POR) for this particular drug was 11.16. This means that the people taking the drug had more than 11 times the odds of gaining weight compared to the people who were taking a placebo.