Exploring the Reach and Representativeness of Participants Enrolled in a Behavioral Intervention Targeting Sugar-Sweetened Beverage Consumption

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Virginia Tech


BACKGROUND: Understanding the reach and representativeness of participants enrolled in behavioral trials, including nutrition and physical activity trials, helps inform the generalizability of study findings and potential public health impacts. Exploring the reach and representativeness of trials that target low socioeconomic and low health literate participants in rural and medically underserved areas, such as southwest Virginia (SWVA), is especially important. The proposed research is part of Talking Health, a six-month, pragmatic randomized-control trial aimed at decreasing sugar-sweetened beverage (SSB) consumption (SIPsmartER) as compared to matched contact control targeting improving physical activity (MoveMore). This community-based trial targets an 8-county region in SWVA. OBJECTIVES: Guided by the reach dimension of the RE-AIM framework, the primary objectives of this study were to determine if eligible and enrolled participants in the Talking Health trial were representative of: 1) eligible, but declined participants, and 2) the broader targeted 8-county region based on 2010 US county level census data. We hypothesized that eligible and enrolled participants would be represented in terms of age, race, ethnicity, educational attainment, income, and health literacy when compared to eligible and declined participants, as well as to the broader US census data. We also hypothesized that males would be underrepresented. METHODS: Eligibility requirements for the study included being 18 years of age or older, having reliable access to a telephone, drinking 200 kilocalories of SSB per day, and being a resident of SWVA. A variety of recruitment strategies were used such as active recruitment at health departments, free clinics, and local businesses with help from Virginia Cooperative Extension agents along with passive methods such as flyers, newspaper ads, and word of mouth. The eligibility screener included basic demographic information such as gender, age, race, marital status, occupation, income, educational attainment, number of children in household, and insurance provider. The screener also had three validated subjective health literacy questions. Statistical analysis included descriptive statistics, independent sample t-tests, Chi-square tests, and One Way ANOVA tests to examine the representativeness of enrolled participants. RESULTS: In total, 1,056 participants were screened, 620 were eligible (58.7%), and 301 (48.5%) enrolled. On average, demographic data for enrolled participants included: 93% Caucasian; 81.4% female; income of $23,173±$17,144; 32% high school (HS) education; and health literacy score 4.5±2.2(3=High, 15=Low). Among eligible participants, when comparing enrolled vs. declined participants there were significant differences (p<0.05) in educational attainment [enrolled=32% HS, declined=48% HS], health literacy scores [enrolled=4.5(2.2), declined=5.0(3.1)], gender [enrolled=81% female, declined=73% female], age [enrolled=41.8(13.4) years, declined=38.3(13.6) years], and race [enrolled=93% white, declined=88% white]. However there were no significant differences in ethnicity and income. When compared to average US Census data across the eight counties, enrolled participants had a higher educational attainment [enrolled sample=68%HS, Census=58%HS], higher proportion of females [enrolled sample=81%, Census=48%], and lower mean income [enrolled sample= $23,173, Census=$36,675]. There were no meaningful differences in terms of race and ethnicity between the enrolled sample and Census data. DISCUSSION: Contrary to our hypothesis, eligible and enrolled participants differed from non-enrolled participants in terms of age, race, education, and health literacy. Our enrolled sample was slightly older, predominately Caucasian, with higher educational attainment and higher health literacy. However, as hypothesized, there were no significant differences for ethnicity and income status, and men were underrepresented. When the study sample was compared to US Census data, the sample was well represented in terms of age, race, and ethnicity; however, enrolled participants had a much lower average annual income and a higher educational attainment. Men were also underrepresented when compared to the census data. There was no census data to compare health literacy status, which limits information regarding the representativeness of the enrolled sample. Importantly, this study has revealed the representativeness of individuals enrolled in this behavioral trial, helps inform the generalizability of study findings, and identifies future research for community-based studies targeting rural and medically underserved areas in SWVA. For example, future behavioral interventions need concerted recruitment strategies to target males, individuals with lower health literacy status, and individuals with less than a high school degree. Exploring and addressing barriers for study enrollment among these sub-groups is also important.



RE-AIM Framework, Reach, health literacy, sugar-sweetened beverages