Kirt, Christine R.

Objective To identify the optimal incentive protocol for maximising participation while managing study costs during the Voyage trial. Design Prospective cohort (Voyage trial) of colorectal cancer (CRC) incidence and mortality outcomes in individuals screened with multitarget stool DNA (mt-sDNA) served as the population. A subset was randomised to receive postage stamps as a pre-consent incentive, or as a post-consent incentive after completion of the consent and questionnaire. Descriptive statistics from year 1 are reported. Results During year 1 of the Voyage trial, a total of 600 258 individuals with mt-sDNA orders received at Exact Sciences Laboratories were randomly selected and invited to participate. Of those, 26 429 (4.4%) opted in, 14 365 of whom (54.3%) consented. The opt-in and consent samples were similar to the target population with respect to sex but differed by geographic residence and age (p<0.001). For the embedded incentive experiment, 2333 were randomised to the pre-incentive arm, while 2342 were randomised to the post-incentive arm. Overall consent rate in the incentive trial was 56.4% (60.9% for the pre-consent incentive arm (1421/2333) vs 52.0% for the post-consent incentive arm (1217/2342), p<0.001). Cost reduction was observed for the pre-consent incentive group, and higher response rates were seen among older versus younger individuals. Conclusions Pre-consent incentive option was associated with a higher participation rate and lower costs and was used for the remainder of study recruitment. CRC incidence and mortality vary with age; thus, adjusting for differential participation by age and region will be important in analyses of Voyage data. Trial registration number NCT04124406.

Abstract The Voyage Study is a large-scale, prospective cohort study of long-term health outcomes among participants with a valid multi-target stool DNA (mt-sDNA) test order. Recently, the Voyage Study achieved its enrollment target of 150,000 participants. The intent of this descriptive analysis is to provide baseline geographic and socio-demographic characteristics of Voyage Study participants to set the stage for future comparisons to the broader mt-sDNA user population. Participants were randomly selected from all persons in the U.S. or Puerto Rico who had a valid order for mt-sDNA screening during the enrollment period (10/18/2019 - 10/17/2023). Enrolled participants completed a baseline questionnaire that collected socio-demographic and health information. Participant characteristics and baseline survey answers were compared between regions using chi-square tests where appropriate. Regional geographic data was aggregated for the broader mt-sDNA user population during the enrollment period, though no formal comparisons were made between the broader population and the Voyage population at this time. Analyses were limited to 139,369 participants with available baseline questionnaire data. Voyage participants were more likely to reside in the Midwest, Northeast, or Southeast (29.9%, 22.5%, 22.6% respectively) and less likely to reside in the Southwest and West (11.6%, 13.4%). During the enrollment period, differential participation was also observed in the mt-sDNA user population, with the Midwest, Northeast, and Southeast having the greatest proportion (25.4%, 22.2%, 26.7%) and the Southwest and West having the lowest proportion of mt-sDNA users (13.8%, 11.9%). In the Voyage cohort, Midwest participants reported the lowest education attainment as characterized by years of school completed (14.1% high school or below, 59.2% college or greater), while participants in the West reported the highest education attainment (7.9% high school or below, 67.3% college or greater). The West also had the highest percentage of participants reporting an income of $100,000 or greater (51.6%), with the Southeast being the lowest (42.2%), as compared to the other regions. We report here early results of geographic and socio-demographic characteristics from a new research resource that will enable future analyses of health outcomes and behaviors in a population of mt-sDNA users. We observed that the greatest percentage of Voyage participants resided in the Midwest, Northeast, or Southeast, and that there was differential socio-demographic participant characteristics based on region. Future analyses will compare long-term healthcare outcomes and differences in colorectal cancer incidence and mortality between the broader mt-sDNA user population and the Voyage cohort. Citation Format: Allison M. Berry, Jessica A. Grimm, Christine R. Kirt, Emily J. Kirsch, Rachel E. Dixon, Winnie Z. Fan, Kandace A. Bohn, Jennifer St. Sauver, Kathleen J. Yost, Lila J. Finney Rutten, Janet E. Olson. U.S. Geographic and socio-demographic characteristics of Voyage Study participants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3453.

Abstract Background: Adherence to recommended colorectal cancer (CRC) screening among US adults is below the public health target of 80%. The multi-target stool DNA assay (mt-sDNA) is a self-administered CRC screening test that may remove barriers to adherence. To improve understanding of long-term outcomes and the real-world impact of mt-sDNA screening, Mayo Clinic and Exact Sciences Laboratories are collaborating on a prospective cohort study of CRC incidence and mortality outcomes in individuals screened with mt-sDNA. We conducted an embedded experiment to identify the optimal incentive protocol for maximizing participation while managing study costs. Methods: A subset of the opt-in cohort was randomized to receive postage stamps as a pre-consent incentive, or as a post-consent incentive after completion of the consent and questionnaire. Descriptive statistics from year one of recruitment, as well as the incentive experiment, are reported. Results: During year 1 of the Voyage trial, a total of 600,258 individuals with mt-sDNA orders received at Exact Sciences Laboratories were randomly selected and invited to participate. Of those, 26,429 (4.4%) opted in, 14,365 of whom (54.3%) consented. The opt-in and consent samples were similar to the target population with respect to sex but differed by geographic residence and age (p<0.001). For the embedded incentive experiment, 2,333 were randomized to the pre-incentive arm while 2,342 were randomized to the post-incentive arm. Overall consent rate in the incentive trial was 56.4% (60.9% for the pre-consent incentive arm (1421/2333) vs. 52.0% for the post-consent incentive arm (1217/2432), p<0.001). A cost reduction was observed for the pre-consent incentive group. Higher response rates were seen among older vs. younger individuals, reflecting a common pattern in healthcare-related survey research participation. Age adjusted incidence rates for CRC have been shown to vary regionally; thus, adjustment for differential response by region will be important to ensure representativeness. Conclusions: CRC incidence and mortality vary with age; thus, adjusting for differential participation by age will be important in analyses of Voyage data. Pre-consent incentive option was associated with a higher participation rate and lower costs, and will be used for the remainder of the study recruitment. Trial Registration: NCT04124406; October 11th, 2019

Introduction Population-level screening has been shown to reduce the incidence and mortality of colorectal cancer (CRC). Unfortunately, adherence to screening recommendations among eligible US adults remains below national goals. A relatively new non-invasive screening modality, the Food and Drug Administration–approved multi-target stool DNA (mt-sDNA) assay (commercialised as Cologuard), which combines the detection of haemoglobin and DNA abnormalities, has been completed by more than 3 million individuals. Given mt-sDNA’s recent availability, the effectiveness of mt-sDNA screening with respect to CRC incidence and mortality reduction has not yet been established. Methods and analysis Through an academic–industry collaboration, a prospective cohort study (Voyage) was designed with an initial enrolment target of 150 000 individuals with mt-sDNA ordered by their healthcare provider for CRC screening. Consented participants will be asked to complete a baseline questionnaire to collect sociodemographic and health information. Additional questionnaires will be provided after 1 year, and every 3 years thereafter, to collect data regarding CRC screening follow-up in order to estimate rates of CRC incidence and other health outcomes. Linkage to the National Death Index will be used to estimate mortality rates. Ethics and dissemination The Voyage study will be conducted in accordance with international guidelines and local regulatory requirements and laws. Data will be stored and retained at Mayo Clinic. Only limited data elements required for research purposes will be transmitted between Mayo Clinic and Exact Sciences Laboratories. Results of the Voyage study will be disseminated through scientific presentations and publications. Trial registration number NCT04124406.