PS2-10: The Potential Use of Area-Based Population Characteristics for Targeted Selection and Balancing of Recruitment into Health Literacy Interventions

Abstract

Background and Aims: Individual-level socioeconomic are rarely available for enrollees of health care systems in the US. Research to selectively target participation from, or to balance recruitment across, specific socioeconomic subgroups must rely on other measures. We used of area-based measures from US Census tract records to target participant recruitment by level of formal education and race into a health literacy study. Our objectives were to obtain balanced proportions of participants: with a high school (HS) education or less, and who were African American (AA) or white. Methods: Kaiser Permanente Georgia (KPG) is one of 3 sites participating in an NCI-funded study to develop and evaluate a computer-based assessment of health literacy. At KPG, the goal is to recruit 300 participants from enrollees 25–74 years of age who were geocoded to their US Census tract using residential addresses (N=185,150). Census tracts were linked to US Census SF-3 data to obtain percent AA) residents and percent of adults with a HS education or less in each tract. Approximately 400 participants were randomly selected from each of 9 strata defined by high, moderate, and low tertiles of percent AA residents and, within each tertile of AA, into tertiles of percent of adults with a HS education or less. Results: 189 assessments have been completed among 1,947 invited to date. 58.7% (N=111) of participants were AA; 34.9% (N=66) were white. Self-reported race and formal education of participants paralleled the percent AA residents and percent adults with a HS education or less in the US Census tracts. By race tertiles, 85%, 57%, and 16% of participants were AA compared to 86%, 24%, and 4% of US Census tract residents. By education tertiles, 33%, 19%, and 10% of participants had a HS education or less compared to 56%, 32%, and 22% of US Census tract adults. Conclusions: Initial results indicate this sampling strategy is achieving study goals of recruitment of proportional numbers of AA and white participants and, within race, adequate numbers with a HS education or less. Area-based measures of race and education may facilitate targeted recruitment in the absence of individual-level data.