A review of strategies used to retain participants in clinical research during an infectious disease outbreak: The PREVAIL I Ebola vaccine trial experience

INTRODUCTION: This article describes a retrospective review of participant follow-up and retention strategies in the Partnership for Research on the Ebola Virus in Liberia (PREVAIL) I Vaccine Trial. It illustrates and analyzes strategies used to retain participants in an emergency clinical research response vaccine trial conducted during the 2014 Ebola outbreak in Liberia. METHODS: An anecdotal review of participant retention strategies developed and employed during the PREVAIL I vaccine trial. RESULTS: Though other factors likely contributed to the high retention rate of trial participants, the unique PREVAIL I follow-up process described resulted in an exceptionally high participant retention rate (97.8%) through 12 months of follow-up, increased the ability to obtain meaningful trial results, and provided a platform through which to respond to social issues in an emergency clinical research response setting. CONCLUSION: Successful strategies were developed and employed in the PREVAIL I vaccine trial that resulted in extraordinarily high participant retention and follow-up rates during an infectious disease outbreak. This review illustrates that employing host country social mobilization concepts within a modified clinical research management framework is highly correlated to elevated rates of retention and minimal loss to follow-up. These strategies also contributed to increased data quality and enhanced adherence to protocol requirements. The increased ability to respond to social issues such as stigma, job retention and relationship conflicts was an additional and significant benefit of this follow-up methodology.