What is a primary endpoint?

What is a primary endpoint?

• A. Time to trial completion.
• B. Main outcome used to evaluate treatment effect.
• C. Total sample size.
• D. Any observed adverse event.

Answer: (B)

The primary endpoint is the main outcome the study is designed to assess to determine whether the treatment has a meaningful effect. It is the central result used to judge efficacy and is specified before data collection so the study can be properly powered to detect a difference. This outcome drives the statistical analysis and is the primary basis for concluding whether the treatment works. Time to trial completion is about logistics and duration, not the treatment’s effect. Total sample size is a planning/design parameter, not an outcome measured to judge efficacy. An observed adverse event is a safety observation and, while important, is typically considered a secondary endpoint or part of safety analyses rather than the primary measure of treatment effect. For example, in a cancer trial the primary endpoint might be progression-free survival, while adverse events would be analyzed separately for safety.

The primary endpoint is the main outcome the study is designed to assess to determine whether the treatment has a meaningful effect. It is the central result used to judge efficacy and is specified before data collection so the study can be properly powered to detect a difference. This outcome drives the statistical analysis and is the primary basis for concluding whether the treatment works.

Time to trial completion is about logistics and duration, not the treatment’s effect. Total sample size is a planning/design parameter, not an outcome measured to judge efficacy. An observed adverse event is a safety observation and, while important, is typically considered a secondary endpoint or part of safety analyses rather than the primary measure of treatment effect. For example, in a cancer trial the primary endpoint might be progression-free survival, while adverse events would be analyzed separately for safety.