Project Overview +

Two experiments examine the effects of tailored testimonials on people's knowledge, satisfaction, interest in shared decision-making, and behavioral intentions after reading a colorectal cancer screening decision aid.

Aims +

Aim 1. Examine whether tailored testimonials can improve decision aid outcomes such as knowledge, satisfaction, interest in shared decision-making, and behavioral intentions.

Aim 2. Test mediators through which tailored testimonials have effects.

Participants +

Study 1 includes 1600 participants (2x2 design, 400 per cell) between ages 49-55, have never been screened for colorectal cancer (CRC).

Study 2 recruits the same participant total with the same characteristics as Study 1, but does not recruit any individual who participated in Study 1.

Participants for both studies are recruited from an online panel of people who agree to participate in online surveys (e.g., Survey Sampling, Inc. or SSI).

Intervention +

Study 1: The baseline survey measures participants' perceptions of the importance of barriers and benefits of screening for CRC. Then participants are presented with a decision aid about CRC and screening. Throughout the decision aid, participants are exposed to testimonials from (supposedly) others who have gone through the decision aid before. We manipulate the testimonials using a 2 (perceived Barrier*match/mismatch) x 2 (perceived Benefit*match/mismatch) design.

Study 2: The baseline survey measures participants' perceived susceptibility of developing CRC and health locus of control. Then participants are presented with a decision aid about CRC and screening. Throughout the decision aid, participants are exposed to testimonials from (supposedly) others who have gone through the decision aid before. We manipulate the testimonials using a 2 (Perceived Susceptibility*match/mismatch) x 2 (Health Locus of Control*match/mismatch) design.

The purpose of both studies is to see how the different types of testimonials affect outcomes such as knowledge, interest in shared decision-making, and intentions. We also test how the testimonials affect potential mediators like personal relevance and self-efficacy.

Findings +

We tested a narrative intervention in which a demographically similar person discussed feelings related to barriers of screening. The similar other expressed concern about the various barriers, and then later discovered that these concerns had been overestimated. Compared to a control group who received an educational message about screening without the narrative, participants who received the message with the narrative reported that the barriers would have less of an impact on a future screening experience. Those who saw the narrative also reported they felt at greater risk of colon cancer and they were more interested in screening in the next year. 

The narratives in the current study increased cancer risk perception. We believe that in our study, being in the narrative group increased risk perception of colorectal cancer because the character in the narrative may have increased the salience of risk of the disease.

The present study would suggest that narratives may bias risk perception and treatment choice in an informed decision-making context. The findings support the suggestion by Winterbottom and others (2008) that caution should be exercised when using narratives in informed decision-making interventions. 

We observed a null effect of narrative on knowledge. However, the message in the present study was personally relevant to all participants (i.e., all participants were of the screening age). Researchers have argued that personal relevance may be the most important variable in recipient attention to a message (Brinol & Petty, 2006). Because it was personally relevant, all participants may have attended equally to the message regardless of whether a narrative was included.

Conclusion +

The present study used a narrative intervention that reduced perceptions of the impact of barriers on colorectal cancer screening. The narrative increased perceived risk for colorectal cancer as well as interest in screening. More studies that systematically develop narratives according to theoretical predictions are needed. In addition, longitudinal studies are needed to test mechanisms through which narratives may have effects. These research initiatives will provide insight into the best use of narratives as a health behavior change strategy.