An Evaluation of Recruitment Methods for a Large Glaucoma Genetics Study of African Americans

Abstract

Purpose : Genetic association studies often struggle to reach the enrollment targets required for statistical power, particularly when targeting minority populations. We compared the efficacy, cost, and benefits/drawbacks of recruitment methods employed by the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study.

Methods : The POAAGG study enrolled 10,079 subjects between July 2010-August 2018, from University of Pennsylvania (UPenn) ophthalmology clinics, external ophthalmology clinics (academic medical centers and private practice), sampling of patients who contributed DNA to the Penn Medicine Biobank, and community outreach efforts. We calculated the enrollment yield and cost per subject for each recruitment method and evaluated trends over time.

Results : The majority of subjects were recruited from clinics at UPenn (64%) and external sites (13%) at moderate costs ($134/patient and $131/patient, respectively) (Table 1). Biobank recruitment incurred the lowest cost ($5/patient), but provided few known glaucoma cases (n=31) with limited phenotypic data. Community outreach efforts were highest in cost ($946/patient) with lower enrollment yield (n=224), but provided free glaucoma screening as benefit to the community. Personnel costs accounted for the large majority of recruitment expenses (71%). Monthly case enrollment declined as the local pool of eligible glaucoma patients was depleted, despite an increase in effort (Figure 1).

Conclusions : Meeting high recruitment goals for genetic studies is best accomplished with multiple methods. The POAAGG study enrolled the majority of subjects from UPenn ophthalmology clinics at reasonable cost. However, monthly enrollment declined over time as the pool of eligible cases grew smaller. Supplementation of this source with expansion to external sites and biobank sampling helped us to exceed enrollment goals ahead of schedule. Community outreach provided a direct benefit to participants (free glaucoma screening), but was the least cost-efficient form of recruitment. The POAAGG experience may aid other researchers in designing and budgeting recruitment efforts for large genetic studies.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Figure 1: Monthly case enrollment declined over time, despite an increase in the number of Clinical Research Coordinators employed each month.

 

Table 1: Cost and Enrollment Yield for Recruitment Methods in the POAAGG Study.