Shorter-Form Messaging May Be Preferable for Trial Recruitment
By Elana Gotkine HealthDay Reporter
TUESDAY, July 8, 2025 -- Shorter-form messaging seems to be preferable for recruiting participants to enroll in clinical trials, according to a research letter published online June 25 in the Journal of the American Medical Association.
Niklas Dyrby Johansen, M.D., Ph.D., from Copenhagen University Hospital in Denmark, and colleagues examined whether varying digital recruitment letter layout and color scheme would impact trial enrollment in a randomized experiment conducted within the context of the DANFLU-2 (A Pragmatic Randomized Trial to Evaluate the Effectiveness of High-Dose Quadrivalent Influenza Vaccine vs Standard-Dose Quadrivalent Influenza Vaccine in Older Adults) trial. Layout and color scheme were varied in a 3x3 factorial design. Invitees were randomly assigned to receive one of three layout variants -- a single-page letter, two-page letter, or enhanced two-page letter with additional colored text boxes -- and to receive one of three color schemes (dark red, blue, or green). Across all letters, the text content was identical.
A total of 934,049 Danish citizens aged 65 years and older were randomly assigned to receive different letter types; letters were successfully delivered to 99.95 percent. Overall, 160,451 participants were enrolled in DANFLU-2 during the 2023 to 2024 season. The researchers found that enrollment in DANFLU-2 was significantly more likely among participants who received the single-page letter versus the two-page letter and enhanced two-page letter (16.28 percent versus 16.02 and 15.29 percent, respectively). Across the color schemes, no differences were observed. There were no interactions noted between letter layout and color scheme.
"These findings do underline the importance of carefully considering design and style of participant-facing material in clinical trials, including recruitment letters, particularly in decentralized pragmatic trials where broadly distributed, low-touch recruitment strategies are often necessary," the authors write.
Several authors disclosed ties to pharmaceutical companies, including Sanofi, which funded the DANFLU-2 trial.
Abstract/Full Text (subscription or payment may be required)
Editorial (subscription or payment may be required)
Disclaimer: Statistical data in medical articles provide general trends and do not pertain to individuals. Individual factors can vary greatly. Always seek personalized medical advice for individual healthcare decisions.
© 2025 HealthDay. All rights reserved.
Posted July 2025
Read this next
ENDO: Sweeteners, Genetic Predisposition Independently Linked to Early Puberty
TUESDAY, July 15, 2025 -- Sweetener consumption and genetic predisposition are independently associated with the risk for central precocious puberty (CPP), according to a study...
Diagnostic Model Based on Delayed Post-Gadolinium Enhancement MRI Accurate for Meniere Disease
TUESDAY, July 15, 2025 -- A diagnostic model based on delayed post-gadolinium enhancement magnetic resonance imaging (DEMRI) improves the accuracy of Meniere disease (MD)...
Atopic Dermatitis May Be Linked to Increased Risk for CKD
TUESDAY, July 15, 2025 -- Atopic dermatitis (AD) was associated with an increased risk for chronic kidney disease (CKD) in an Asian population, according to a study published...
More news resources
- FDA Medwatch Drug Alerts
- Daily MedNews
- News for Health Professionals
- New Drug Approvals
- New Drug Applications
- Drug Shortages
- Clinical Trial Results
- Generic Drug Approvals
Subscribe to our newsletter
Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.