Theoretical Background and research questions/hypothesis: Colorectal cancer is the second leading cause of cancer death in the US. Current screening guidelines recommend that people start regular screening at age 50. Colorectal cancer screening tests check for blood in the stool or use an instrument to look at the lining of the colon and rectum. The Screen for Life (SFL) campaign was launched by the CDC in 1999. The SFL campaign is designed to inform people age 50 and older about the importance of having regular colorectal cancer screening tests. Previous research has examined SFL message exposure and screening rates but, to date, no research has examined the persuasive appeals present in campaign messages. The purpose of this study was to evaluate the content of the messages being distributed in the SFL campaign. The types of persuasive appeals present in campaign messages were identified and classified. Persuasive message design theories provide guidance regarding the most effective ways to change attitudes and behaviors. Message design features include: Emotional appeals, evidence type, message sidedness, efficacy, norms, attitude functions, message frame, and characteristics of the source. This project was a systematic analysis of these persuasive message design features.
Methods: A content analysis of campaign materials from the current SFL campaign was conducted. Four coders were trained to use a codebook developed to assess persuasive message design features. To establish inter-coder reliability all campaign materials were coded by all four coders. The average pairwise Cohen’s kappa was 0.94. The average pairwise percent agreement was 98.33.
Results: In the campaign, 43.80% of messages included emotional appeals. Guilt (10.90%), humor (9.40%), warmth (32.80%), fear (68.80%), and hope (70.30%) were all present. When fear was present 26.60% of messages mentioned severity and 62.50% mentioned susceptibility. Quantitative evidence was present in 73.40% of messages. Within this category, 67.20% presented frequency data, 6.30% had percentage data, 3.10% had probability data, and 31.30% made verbal statements of probability. Qualitative evidence was present in 25.00% of messages. Most arguments were one sided (85.90%). The majority of the messages mentioned injunctive norms (95.30%) and fewer mentioned descriptive norms (20.30%). In terms of attitude functions, most messages presented a utilitarian function (93.80%). Far fewer presented a knowledge function (46.90%), an ego-defensive function (3.10%), a social identify function (29.70%), or a value expressive function (15.60%). Most message were gain frame (92.20%) with only 18.80% loss frame.
Conclusions: Screening among those age 50 and older has increased in the last decade. Nevertheless, 1 in 3 adults is not up to date with recommended screenings. Little research has systematically evaluated the breadth of message characteristics present in large scale behavior change initiatives. This analysis provides a complete understanding of the types of persuasive appeals being utilized in the SFL campaign. There is an opportunity for message designers to utilize persuasion and message design theory to increase message effectiveness.
Implications for research and/or practice: Recommendations for message design are put forth including: The use of response efficacy, the inclusion of descriptive norms, and a cautionary note regarding the use of fear appeals.