Shorter-form messaging has been found to be more effective in recruiting participants for clinical trials, a recent study published in the Journal of the American Medical Association revealed. The study, conducted by Niklas Dyrby Johansen, M.D., Ph.D., and colleagues from Copenhagen University Hospital in Denmark, aimed to investigate the impact of digital recruitment letter layout and color scheme on trial enrollment.
In the randomized experiment, participants were assigned to receive one of three layout variants—a single-page letter, two-page letter, or an enhanced two-page letter with additional colored text boxes. They were also assigned one of three color schemes—dark red, blue, or green. Despite identical text content across all letters, the researchers found that enrollment in the trial was significantly higher among those who received the single-page letter compared to the two-page letter and enhanced two-page letter.
A total of 934,049 Danish citizens aged 65 years and older were included in the study, with letters successfully delivered to 99.95% of them. Overall, 160,451 participants were enrolled in the trial during the 2023 to 2024 season. Interestingly, the color scheme did not have a significant impact on enrollment rates, and there were no interactions observed between the letter layout and color scheme. These findings emphasize the importance of carefully designing participant-facing materials in clinical trials, especially in decentralized pragmatic trials where effective recruitment strategies are crucial.
For those interested in delving deeper into this topic, the research letter titled “Randomized Experiment of Recruitment Letter Design to Maximize Clinical Trial Enrollment” published in JAMA provides more detailed information. Additionally, the study titled “Trials Within Trials—Optimizing the Delivery of RCTs” in JAMA offers further insights into enhancing recruitment strategies for clinical trials.
In conclusion, the study highlights the significance of utilizing shorter-form messaging in recruitment letters for clinical trials to improve enrollment rates. By considering the design and style of participant-facing materials, researchers can optimize recruitment strategies and enhance the success of clinical trials. This research contributes valuable insights to the field of healthcare and emphasizes the importance of effective communication in clinical trial recruitment efforts.
References:
– Niklas Dyrby Johansen et al, Randomized Experiment of Recruitment Letter Design to Maximize Clinical Trial Enrollment, JAMA (2025). DOI: 10.1001/jama.2025.9170
– Sean W. X. Ong et al, Trials Within Trials—Optimizing the Delivery of RCTs, JAMA (2025). DOI: 10.1001/jama.2025.10107
Source: 2025 HealthDay. All rights reserved.
