Recruitment strategies and lessons learned from a large genetic study of African Americans.

Genetic studies must enroll large numbers of participants to obtain adequate statistical power. Data are needed on how researchers can best use limited financial and practical resources to achieve these targets, especially in under-represented populations. This paper provides a retrospective analysis of the recruitment strategies for a large glaucoma genetics study in African Americans. The Primary Open-Angle African American Glaucoma Genetics study enrolled 10,192 African American subjects from the Philadelphia region. Major recruitment approaches included clinic enrollment from University of Pennsylvania (UPenn) sites, clinic enrollment from external sites, sampling of Penn Medicine Biobank (PMBB), and community outreach. We calculated the enrollment yield, cost per subject, and seasonal trends of these approaches. The majority (65%) of subject were enrolled from UPenn sites with an average cost of $133/subject. Over time, monthly case enrollment declined as the pool of eligible subjects was depleted. Expanding to external sites boosted case numbers ($129/subject) and the biobank provided additional controls at low cost ($5/subject), in large part due to the generosity of PMBB providing samples free of cost. Community outreach was costly with low return on enrollment ($978/subject for 220 subjects). Summer months (Jun-Aug) produced the highest recruitment yields (p<0.001). Genetic studies will benefit from a multi-pronged and culturally sensitive recruitment approach. In our experience, the biobank was most cost-effective for control enrollment, while recruitment from clinics (including expansion to new sites) was necessary to recruit fully phenotyped cases.

A Precise Method to Evaluate 360 Degree Measures of Optic Cup and Disc Morphology in an African American Cohort and Its Genetic Applications.

(1) Background: Vertical cup-to-disc ratio (CDR) is an important measure for evaluating damage to the optic nerve head (ONH) in glaucoma patients. However, this measure often does not fully capture the irregular cupping observed in glaucomatous nerves. We developed and evaluated a method to measure cup-to-disc ratio (CDR) at all 360 degrees of the ONH. (2) Methods: Non-physician graders from the Scheie Reading Center outlined the cup and disc on digital stereo color disc images from African American patients enrolled in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. After converting the resultant coordinates into polar representation, the CDR at each 360-degree location of the ONH was obtained. We compared grader VCDR values with clinical VCDR values, using Spearman correlation analysis, and validated significant genetic associations with clinical VCDR, using grader VCDR values. (3) Results: Graders delineated outlines of the cup contour and disc boundaries twice in each of 1815 stereo disc images. For both cases and controls, the mean CDR was highest at the horizontal bisector, particularly in the temporal region, as compared to other degree locations. There was a good correlation between grader CDR at the vertical bisector and clinical VCDR (Spearman Correlation OD: r = 0.78 [95% CI: 0.76-0.79]). An SNP in the MPDZ gene, associated with clinical VCDR in a prior genome-wide association study, showed a significant association with grader VCDR (p = 0.01) and grader CDR area ratio (p = 0.02). (4) Conclusions: The CDR of both glaucomatous and non-glaucomatous eyes varies by degree location, with the highest measurements in the temporal region of the eye. This method can be useful for capturing innate eccentric ONH morphology, tracking disease progression, and identifying genetic associations.

Evaluation of a multimedia marketing campaign to engage African American patients in glaucoma screening.

Our objective was to determine which messaging approaches from a marketing campaign were most effective in recruiting African American individuals to a glaucoma screening and research study. We conducted a multimedia marketing campaign in Philadelphia from 01/31/2018 to 06/30/2018. Messaging approaches included radio advertisements and interviews (conducted in partnership with a local radio station with a large African American listener base), print materials, event tables, and online postings. Participants received free glaucoma screenings and the opportunity to enroll in our glaucoma genetics study. These screenings allowed individuals with glaucoma to receive a full examination and treatment plan with a glaucoma specialist, as well as to contribute to future efforts to identify genetic variants underlying this disease. We compared inquiry, enrollment, and cost yield for each messaging approach. Our campaign resulted in 154 unique inquiries, with 98 patients receiving glaucoma screenings (64%) and 60 patients enrolling in our study (39%). Commercials on WURD radio yielded the highest number of inquiries (62%) and enrollments (62%), but at relatively high cost ($814/enrolled patient). The most inexpensive approach that yielded more than five enrollments was postcards ($429/enrolled patient). Our campaign suggests that high-frequency commercials and postcards distributed at targeted healthcare locations are particularly effective and affordable options for connecting with the African American community. Our findings can help to inform recruitment efforts for other understudied diseases in minority populations.

The association of mitochondrial DNA haplogroups with POAG in African Americans.

Mitochondrial dysfunction has been implicated in the pathogenesis of primary open-angle glaucoma (POAG). However, the potential significance of mitochondrial DNA (mtDNA) haplogroups to POAG has not been evaluated in the overaffected African American population. To investigate the association of mtDNA haplogroups with POAG and its phenotypic characteristics, genotyping data from 4081 African American subjects (1919 cases and 2162 controls) was analyzed using 1293 positions on mtDNA. The overall frequency of mtDNA haplogroups in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study cohort was 37% L3, 29% L2, 21% L1, 4% L0, and 10% non-African haplogroups (non-L). When all haplogroups (L0, L1, L2, and non-L) were compared against theL3 reference group, after adjusting by age and principal component of ancestry, the non-L3 haplogroups showed higher risk of POAG (OR-1.19, p = 0.02), with a particularly strong association among males (OR = 1.41, p = 0.003). More specifically the non-L group was associated with higher POAG risk than the L3 haplogroup (OR = 1.77, p = 0.007, Bonferroni adjusted p = 0.027) and to the L3e (n = 256, OR = 1.92, p = 0.007, Bonferroni adjusted p = 0.029). No significant association was found when genders were analyzed together or in female only analysis. There were no significant differences in various POAG endophenotypes across mtDNA haplogroups. This study expands our knowledge of mitochondrial genetics and mtDNA haplogroup associations in African American POAG. Further work is needed to better understand the functional role of mtDNA polymorphisms and their interactions with nuclear genes that affect POAG.

Cost and yield considerations when expanding recruitment for genetic studies: the primary open-angle African American glaucoma genetics study.

BACKGROUND: African Americans have been historically under-represented in genetic studies. More research is needed on effective recruitment strategies for this population, especially on approaches that supplement traditional clinic enrollment. This study evaluates the cost and efficacy of four supplemental recruitment methods employed by the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. METHODS: After enrolling 2304 patients from University of Pennsylvania ophthalmology clinics, the POAAGG study implemented four new recruitment methods to supplement clinic enrollment. These methods included: 1) outreach in the local community, 2) in-house screening of community members ("in-reach"), 3) expansion to two external sites, and 4) sampling of the Penn Medicine Biobank. The cost per subject was calculated for each method and enrollment among cases, controls, and suspects was reported. RESULTS: The biobank offered the lowest cost ($5/subject) and highest enrollment yield (n = 2073) of the four methods, but provided very few glaucoma cases (n = 31). External sites provided 88% of cases recruited from the four methods (n = 388; $85/subject), but case enrollment at these sites declined over the next 9 months as the pool of eligible subjects was depleted. Outreach and in-reach screenings of community members were very high cost for low return on enrollment ($569/subject for 102 subjects and $606/subject for 45 subjects, respectively). CONCLUSIONS: The biobank offered the most cost-effective method for control enrollment, while expansion to external sites was necessary to recruit richly phenotyped cases. These recruitment methods helped the POAAGG study to exceed enrollment of the discovery cohort (n = 5500) 6 months in advance of the predicated deadline and could be adopted by other large genetic studies seeking to supplement clinic enrollment.