Increasing CRC Screening in Primary Care Settings

Regular screening reduces both morbidity and mortality from colorectal cancer (CRC). Screening rates, however, remain low suggesting the need for innovative research designed to increase screening behavior. The purpose of this study is to compare the effectiveness of two interventions (Tailored Health Communication [THC] and Motivational Interviewing [MI]) in increasing CRC screening behavior. Both interventions are based on a strong conceptual framework derived from the Health Belief Model (HBM) and Transtheoretical Model (TTM), allowing us to explore the underlying mechanisms through which these interventions impact behavior change.

The primary aim of this study is to compare CRC screening test use among 804 participants randomly allocated to control or intervention conditions; participants will be recruited from the two sites (Chicago, IL, and Nashville, TN). The 3 study groups will receive (1) standard care, (2) tailored health communication, and (3) motivational interviewing. Eligibility criteria for study participants includes being 50 years or older, not having CRC, and being of average or moderate risk for CRC. Study participants will be surveyed by telephone about CRC-related beliefs pre-intervention (Time 1), 1 month postintervention (Time 2), and at 6 months postintervention (Times 3 and 4, respectively). Dichotomous behavioral outcomes (had screening test or not) and stages of CRC screening test adoption (based on the TTM) will be assessed, as well as sociodemographic and belief predictors of screening behavior. Binomial and multinomial logistic regression models will be used to evaluate screening test use and stage of test adoption. Sociodemographic and belief variables will be used as covariates, with intervention group as the primary independent predictor. Descriptive statistics and ANOVA will be employed to assess between intervention differences in amenable beliefs. Path (mediation) analysis will be performed to further explore the underlying mechanisms through which THC and MI may differentially affect CRC screening behavior.