Implementation intentions and colorectal screening: a randomized trial in safety-net clinics

Low-income and racial/ethnic minority populations experience disproportionate colorectal cancer (CRC) burden and poorer survival. Novel behavioral strategies are needed to improve screening rates in these groups.

The study aimed to test a theoretically based "implementation intentions" intervention for improving CRC screening among unscreened adults in urban safety-net clinics.

Randomized controlled trial.

Adults (N=470) aged ≥50 years, due for CRC screening, from urban safety-net clinics were recruited.

The intervention (conducted in 2009-2011) was delivered via touchscreen computers that tailored informational messages to decisional stage and screening barriers. The computer then randomized participants to generic health information on diet and exercise (Comparison group) or "implementation intentions" questions and planning (Experimental group) specific to the CRC screening test chosen (fecal immunochemical test or colonoscopy).

The primary study outcome was completion of CRC screening at 26 weeks based on test reports (analysis conducted in 2012-2013).

The study population had a mean age of 57 years and was 42% non-Hispanic African American, 28% non-Hispanic white, and 27% Hispanic. Those receiving the implementation intentions-based intervention had higher odds (AOR=1.83, 95% CI=1.23, 2.73) of completing CRC screening than the Comparison group. Those with higher self-efficacy for screening (AOR=1.57, 95% CI=1.03, 2.39), history of asthma (AOR=2.20, 95% CI=1.26, 3.84), no history of diabetes (AOR=1.86, 95% CI=1.21, 2.86), and reporting they had never heard that "cutting on cancer" makes it spread (AOR=1.78, 95% CI=1.16, 2.72) were more likely to complete CRC screening.

The results of this study suggest that programs incorporating an implementation intentions approach can contribute to successful completion of CRC screening even among very low-income and diverse primary care populations. Future initiatives to reduce CRC incidence and mortality disparities may be able to employ implementation intentions in large-scale efforts to encourage screening and prevention behaviors.