Secondary Endpoint
An additional outcome measure providing supporting evidence about a drug's effects beyond the primary endpoint. In weight management trials, secondary endpoints may include waist circumference, blood pressure, lipid levels, and quality of life measures.
Technical Context
Secondary endpoints are hierarchically tested (using a gatekeeping strategy) to control the overall false positive rate. Only if the primary endpoint is statistically significant can secondary endpoints be formally tested in a pre-specified order. If any secondary endpoint fails, all subsequent endpoints in the hierarchy are considered exploratory (not confirmatory). In GLP-1 RA weight management trials, the hierarchical secondary endpoint order might be: ≥10% weight loss proportion → ≥15% weight loss proportion → waist circumference change → systolic BP change → lipid changes → PRO measures. This hierarchy is pre-registered and reflects clinical importance priorities. Additional endpoints tested outside the hierarchy are considered exploratory regardless of their p-values.