Abstract: Developing a Digital Decision Aid to Promote Home Stool Screening for Colorectal Cancer: A Patient-Tailored Risk Factor Strategy

◆ Naomi Parker, University of Florida
◆ Jordan M. Neil, Harvard Medical School
◆ Yulia Strekalova, University of Florida
◆ Janice L. Krieger, University of Florida

In the United States, colorectal cancer (CRC) is the second leading cause of cancer death in men and women. Early detection, through timely screening, is an effective method to reduce preventable CRC-related incidence and mortality. However, current screening rates remain suboptimal. In part, this is due to poor patient knowledge of alternative and less invasive screening strategies, such as home tool screening. Further, the majority of patient decision-aids that address home stool screening do not provide tailored risk information, reducing patient perceptions of informational relevance and susceptibility to CRC. The primary aim of this study, therefore, was to examine how message styles influence behavioral intentions to screen with a home stool test. By drawing on the Elaboration Likelihood Model and the Health Belief Model, the current study evaluated the effectiveness of a patient-tailored risk factor strategy on screening intentions, as well as the mediating effects of perceived message relevance and perceived susceptibility on intentions to screen with a home stool test.
Participants (N=377) were recruited using Qualtrics Panels, a proprietary opt-in online panel company. The survey was disseminated during the Colorectal Cancer Awareness Month (March 30-31, 2015). Participants met national CRC screening eligibility criteria and were randomized to receive one of two message conditions: (1) a generic CRC digital decision aid promoting use of home stool screening or (2) a tailored CRC digital decision aid. Both decision aids included information on risk factors for CRC, with the tailored message condition displaying patient-tailored feedback about their CRC risk factors.
There were no significant differences in main effects between message conditions on intent to screen with a home stool test. Adjusted for participant demographics, screening history, and a composite behavioral risk score for CRC, a path-based analytical framework for serial mediation was conducted. Message conditions were included as a predictor, perceived message relevance and perceived susceptibility included as the mediators in serial, and intent to screen as the outcome variable. There was no significant direct effect of message condition on intent to screen (b=-.35, t=-1.79, p=.08). However, the tailored message condition was significantly better at increasing perceived message relevance than the generic message condition (b=.33, t=2.47, p<.05), with a greater composite behavioral risk factor score also predicting greater perceived message relevance (b =.19, t=2.53, p<.05). There was no significant, direct relationship between message condition and perceived susceptibility (b = -.01, t =-.07, p=.95), but a greater composite behavioral risk factor score predicted greater susceptibility (b=.21, t=2.73, p<.01). There was a significant indirect effect of the tailored message condition on intent to screen, with statistically significant positive associations between all variables in serial (i.e., tailored message condition→perceived message relevance→perceived susceptibility→intent to screen =.01, SE = .01, 95% bootstrap CI=.02,.04),
The current study’s findings offer practical implications for tailoring CRC digital decision aids to promote home stool screening. The findings also further support existing theoretical frameworks to understand the critical mediating mechanisms (i.e., perceived relevance and susceptibility) that help explain the indirect effect tailoring can have on improving patient willingness to screen for cancer.