Brief and Concise Messaging Enhances Clinical Trial Recruitment Effectiveness

Recent research indicates that using shorter, more straightforward messaging in recruitment letters significantly improves participation rates in clinical trials. A study published in the Journal of the American Medical Association (JAMA) analyzed how variations in the design and presentation of recruitment letters impacted enrollment among older adults in Denmark. The experiment employed a 3x3 factorial design, altering layout and color schemes of invitation letters, which were sent to nearly one million citizens aged 65 and above.

The findings revealed that participants were more likely to enroll when they received a single-page letter or a simplified, enhanced two-page version, compared to a standard two-page letter. Interestingly, the color scheme did not influence enrollment rates. This suggests that clarity and brevity in participant-facing materials are crucial, especially in decentralized or large-scale pragmatic trials where low-touch recruitment strategies are common.

The study underscores the importance of thoughtful design in participant communication, emphasizing that concise messages can facilitate better engagement and improve the success of recruitment efforts in clinical research. These insights are vital for researchers looking to optimize their recruitment strategies and enhance trial efficiency.

Source: https://medicalxpress.com/news/2025-07-shorter-messaging-trial.html