In a research study, the primary outcome, also known as the primary endpoint, is the main result that is measured at the end of a study to assess whether or not the intervention was successful. It is the most significant outcome that directly relates to the research question. The primary outcome is usually specified in the study's objectives and is often the motivation behind conducting the research. For instance, in a clinical trial testing a new drug for treating diabetes, the primary outcome could be the level of blood glucose control achieved.

The primary outcome is usually reported in the results section of the study and is the main focus of the data analysis. The statistical significance of the primary outcome determines the overall interpretation of the study results. For instance, if the primary outcome shows a significant difference between the control and the intervention groups, it suggests that the intervention had an effect. However, it's crucial to remember that even if a primary outcome is statistically significant, it doesn't necessarily mean it is clinically significant or applicable in real-world situations. Therefore, researchers must interpret their findings in a broader context..