Aortic & peripheral vascular disease
Effect of opt-in versus opt-out framing on trial recruitment: a study within a trial of the GAMEPAD randomized trial
Primary result · Enrollment fractionResult — go to the resultOdds ratio 3.65 95% CI 2.37–5.64Authors' conclusion
This SWAT of recruitment strategies demonstrates the potential for opt-out framing and active outreach to increase enrollment fraction without compromising protocol completion in direct-to-participant RCTs.
Study context
- Population
- Eligible patients with PAD contacted for an randomized clinical trial (RCT) of a physical activity interventioncontacted by unsolicited email
- Participants
- 5,176 patients
- Comparison
- Opt-out vs opt-in recruitment framing
- Opt-outn = 1,267
- Opt-inn = 3,909reference
- Primary endpoint
- Enrollment fraction
Primary result
As reported in the abstract
Odds ratio
3.65
95% CI 2.37–5.64
Events by treatment group
Opt-out vs Opt-in
OR 3.65 (95% CI 2.37–5.64)
Further findings
Completion of trial protocol steps
- No significant differences between opt-in and opt-out participants
Original publication
Effect of opt-in versus opt-out framing on trial recruitment: a study within a trial of the GAMEPAD randomized trial. Am Heart J. Published 3 October 2025. doi:10.
Summarised from the published abstract; every number is checked against it