Utilizing Respondent Driven Sampling to assess neurocognitive functioning in the indigenous American Samoa population 60 years or older.

Abstract

AbstractBackgroundRespondent Driven Sampling (RDS) is a cost‐efficient, chain referral sampling method, where respondent seeds recruit others who are eligible within their social networks; those recruited by the seeds then recruit others (Heckathorn, 1997). In American Samoa recruitment of a random population‐based sample is difficult due to systematic error and biases in sample characteristics arising from the hierarchical relationships prominent in American Samoan society (Aitaoto, et al. 2007; Cassel 2010; Cassel, 2014). The INdigenous Samoan Partnership to Initiate Research Excellence (INSPIRE) program recruited 718 participants age 45 and over during a 51‐day period with 20% age 60 or higher. For this reason, RDS methods were utilized to assess neurocognitive functioning in the Samoan population age 60 or over.MethodINSPIRE program staff recruited 60 participants as RDS seeds (30 men and 30 women). Once the seeds completed the data collection process, they were given coupons to recruit a maximum of 3 community members. In addition, they were provided a printed reminder of the eligibility criteria. The patterned continued to create consecutive recruitment waves (Wave 1, n = 60; Wave 2, n = 180; Wave 3, n = 540) until the sample size was reached. Participants received a total $25 incentive for participating in the survey. Additionally, participants will be compensated as RDS recruiters and receive an additional $15 for each recruit who participates, up to a maximum of 3. The RDS recruitment proposed to yield 780 participants, with 390 women and 390 men with a 12% loss to follow up.ResultPreliminary data analysis reveals target sample size was collected in 126 days (41% Male, 59% Female). Referral chain analysis reports only 25% of seeds recruited 80% of participants although social networking sizes varied for the seeds. Some participants with higher social networks did not participate in recruiting.ConclusionIntercept promotions complimented the use of RDS to help identify seeds and include faith‐based institutions (churches), senior centers, civics clubs, village‐based and other networks to recruit men and women, ages 60 and over. Maintaining a central location for study implementation and coupon payment supported ease of access for the study population.