Interventions to increase enrollment in a large multicenter phase 3 trial of carotid stenting vs. endarterectomy

Posted: Oct 01, 2012
International Journal of Stroke. 7. 6. 447-53.
KEYWORDS: Institutional Issues, Inadequate Staffing, Eligibility, Web, Non-Cancer


Multiple complementary recruitment tactics combine to improve accrual.

Why this item may be useful

This article describes multiple approaches used to improve accrual to a large, multicenter, randomized stroke prevention trial that was not meeting its recruitment goals. The authors conclude that no single recruitment method, no matter how effective, can have an impact on accrual equal to that achieved through a coordinated combination of complementary approaches. New strategies used for this trial included adding study sites, hiring a recruitment director, broadening eligibility to include asymptomatic patients, and implementing marketing tactics and trial management improvements. Between 2000 and 2003, when the new strategies were initiated, 54 patients were randomized; between 2003 and 2008, the remainder of the target sample of 2,502 patients were randomized.


  • Factors negatively affecting accrual included extensive credentialing required for one tested procedure, delays in reimbursement for that procedure, and temporary suspension of enrollment due to a protective device failure.
  • Marketing tactics including branding the trial with a study logo, a public-access study Web site, and enhanced recruitment materials.
  • Trial management improvements included creation of a centralized study coordination center; development of site-specific recruitment plans; site visits by national study leaders; congratulatory e-mails sent to site staff for each randomized patient; a bimonthly newsletter recognizing enrollment achievements; annual conferences and periodic teleconferences to discuss protocol updates, compliance issues, training needs, and trial progress; and provision of recruitment tools on a password-protected Web site.
  • Increases in personnel costs associated with the implementation of multiple new recruitment tactics were substantial.
  • The article includes a detailed table of specific tactics used to accelerate enrollment.
Linda Parreco's Image

Thanks to Jamie Roberts for submitting this article to AccrualNet. Be sure to check out the comprehensive list of tactics used in the CREST study.