Table 3. Summary of Results of Trial Extension Studiesa.
| Patterns of Outcomes Reported in the Trial Extension Study | No. (%) | Comments |
|---|---|---|
| Significant benefits of intervention seen in original and extended trial using the same end points as in the original trial | 42 (27.1) | Using the same end point measures, but defined using administrative data in the extended trial |
| Significant benefits of intervention seen in original and extended trial with different end points in the extended trial | 11 (7.1) | Different end points could be, for example, cardiovascular deaths rather than cardiovascular events |
| Significant benefits of intervention seen only in the extended trial using the same end points as in the original trial | 6 (3.9) | Using the same end point measures, but defined using administrative data in the extended trial |
| Significant benefits of intervention seen only in the extended trial using different end points in the extended trial | 15 (9.7) | |
| Equivalence of intervention seen in original and extended trial | 20 (12.9) | Using the same end point measures, but defined using administrative data in the extended trial |
| Equivalence of intervention seen in original and extended trial with different end points in the extended trial | 14 (9.0) | |
| Significant benefits of intervention seen in the original trial were no longer significant in the extended trial | 12 (7.7) | Using the same end point measures, but defined using administrative data in the extended trial |
| Significant harms of intervention seen only in the extended trial | 14 (9.0) | |
| Significant harms seen in original and extended trial | 2 (1.7) | |
| Outcomes in the extended trial were not analyzed according to randomization | 19 (12.3) | For example, observational study of treated cohort only |
a
Includes a total of 155 analyses from 113 study reports.