When designing clinical trials, sometimes we may expect a larger treatment effect in one group while others exhibit an attenuated effect. In these settings there can be a trade-off between a smaller average treatment effect with broader enrollment criteria and a larger effect with restricted criteria but longer enrollment duration. Identification of subgroups will often use a clinical decision rule, for example, biomarker cutoff, but may be imprecise, that is, with sensitivity and specificity not simultaneously 100%. We evaluate the impact of including attenuated subgroups on design operating characteristics and illustrate scenarios where overall trial duration may be shorter by not being restrictive.
Bibliographical noteFunding Information:
This work was supported in part by grant 1UL1RR033183 from the National Center for Research Resources and by grant 8 UL1 TR000114-02 from the National Center for Advancing Translational Sciences of the National Institutes of Health.
- Clinical trial design
- Heterogeneous effects
- Operating characteristics
- Sample size