Degree Name: Psychological Sciences

University: University of California, Merced, 2018

Committee Chair: Linda D. Cameron

Objective: After appraising health threats, personal thoughts and emotions can often influence healthy individuals to engage in protection behaviors. Leventhal’s Common-Sense Model (CSM) of Self-Regulation and Cameron’s Assessment of Illness Risk Representations (AIRR) have provided frameworks for delineating personal risk beliefs, emotional responses, and protection behaviors. Risk beliefs and worry were utilized to develop, pilot, and trial a CSM-guided health communication promoting accurate colorectal cancer (CRC) risk representations and physical activity (PA). Furthermore, the CSM-guided health intervention was developed to be delivered as an online presentation (eHealth) and mobile phone text messages (mHealth).

Methods: Three studies were conducted: (a) mixed-methods approach incorporated Think-Aloud technique and repeated measure, (b) using findings from Study 1, two pilot RCTs determined effectiveness of an intervention and validate measures comprising repeated measures, and (c) a longitudinal RCT tested efficacy. For Study 1, 43 university undergraduates participated. For Study 2, 73 university undergraduates were recruited to participate in a pilot RCT to test feasibility and acceptability of the newly developed CSM-guided health intervention (Be Well program, BW). For Study 3, 40 university undergraduates and 44 participants recruited via social media were randomly assigned to the BW condition or Standard CRC Risk Information condition.

Results: After developing an intervention to promote CRC prevention and physical activity, themes emerged: text and images accurately depicting CRC risk influenced engagement, clearly labeled images matching text were favored, realistic images were rated higher over illustrations, and text in plain language was endorsed. In Study 2, the BW program was found to be acceptable and relevant to healthy younger adults. In Study 3, RCT found more accurate risk representations and physical activity levels in the BW condition. BW condition reported more coherence of link between PA and CRC risk immediately after receiving mHealth. BW program had higher quality, instilled more mental images, and elicited thoughts about CRC risk.

Conclusions: The development of the CSM-guided health intervention for CRC control is described. The BW program was more efficacious in increasing personal understanding of link between cancer risk and PA and PA effort.