Boosting enrolment in clinical trials: validation of a regional network model

Clin Trials. 2011 Oct;8(5):645-53. doi: 10.1177/1740774511414925. Epub 2011 Aug 8.


Background: Clinical trials of stroke therapy have been hampered by slow rates of enrolment.

Purpose: Our purpose is to validate a previously developed model for accelerating enrolment in clinical trials by replicating it at new locations. The model employs coordinators who travel from a host institution to enrol participants from a network of participating hospitals. Active surveillance assures identification of all eligible patients.

Methods: Among 70 U.S. investigators participating in National Institutes of Health-funded trial of stroke prevention, five investigators were invited to develop local identification and outreach networks (LIONs). Each LION comprised a LION coordinating centre servicing multiple hospitals. Hospitals provided names of patients with stroke or transient ischaemic attack to researchers at the LION coordinating centre who initiated contact; patients were offered home visits for consent and randomization. Outcomes were feasibility, enrolment, data quality, and cost.

Results: Five LIONs varied in size from two to eight hospitals. All 24 hospitals we approached agreed to participate. The average monthly rate of enrolment at the research sites increased from 1.4 participants to 3.5 after expanding from a single institution model to the LION format (mean change = 2.1, range 0.9-3.7). Monthly performance improved over time. Data quality was similar for LIONs and non-LION sites, except for drug adherence which was lower at LIONs. The average cost to randomize and follow one participant during the study interval was 2.4 times the cost under the per-patient, cost-reimbursement strategy at non-LION sites. The cost ratio declined from 3.4 in year one to 1.8 in year two.

Limitations: The LION strategy requires unprecedented collaboration and trust among institutions. Applicability beyond stroke requires confirmation.

Conclusion: LIONs are a practical, reproducible method to increase enrolment in trial research. Twelve months were required for the average site to reach its potential. The per-participant cost at LIONs was higher than conventional sites but declined over time.

Publication types

  • Research Support, N.I.H., Extramural
  • Validation Study

MeSH terms

  • Adult
  • Clinical Protocols
  • Clinical Trials as Topic / methods*
  • Feasibility Studies
  • Geography
  • Humans
  • Models, Theoretical*
  • Multicenter Studies as Topic / methods
  • Patient Selection*
  • Research Design
  • Stroke / drug therapy*
  • United States