Colon cancer information as a source of exercise motivation

Abstract

Using a Protective Motivation Theory (PMT) framework, this study examined whether colon cancer is a meaningful source of exercise motivation. Participants were (N = 173) teaching and school staff randomly assigned into one of three treatment conditions: PMT present, PMT absent (attention control) and no information (non-contact control). Two separate DVD videos were developed (one incorporating the four major components of PMT; perceived vulnerability (PV), perceived severity (PS), response efficacy (RE) and self-efficacy (SE) featured colon cancer and exercise information while the other DVDs featured cancer and nutritional information). Following treatment, participants completed questionnaires which assessed their beliefs towards colon cancer and exercise as well as their intentions to do more exercise. Two weeks later (T1), self-reported measures of exercise behaviour were assessed and then repeated at 1 month (T2). Only physically inactive participants were used in subsequent analyses (n = 72). Results indicated that compared to the two control groups, the PMT present group scored significantly higher on RE and intention to engage in more exercise (p-values = 0.001). A trend effect in the expected direction also was noted for T1 exercise behaviour (p = 0.09). RE, SE and PV made significant and unique contributions to exercise intention scores, explaining 44% of the response variance. Intention was the only variable to show an association with T1 exercise behaviour, explaining 10% of the response variance. Overall, these findings suggest that a single exposure of media intervention grounded in theory can influence people's beliefs, motivation and initial behaviour.

Keywords:

• Health promotion
• disease
• message tailoring
• intentions
• physical activity

Acknowledgements

The authors would like to acknowledge the valuable contribution of Drs Bryan and Suzan Perry for their expert commentary on (a) the severity and vulnerability of colon cancer and (b) the benefits of exercise in reducing the risk of colon cancer. The authors would also like to acknowledge Ms Jenny Pearce for her expert commentary on diet and its relationship to cancer in general. Finally, the authors would like to thank Neil Morris and Richard Smith from the Education Media centre for their assistance with filming and editing the intervention material.

All participants were provided the results from the study and those in the attention and non-contact control groups were provided the opportunity to view the PMT intervention.

Notes

Notes

[1] A recent systematic review (Bridle et al., 2005) of the effectiveness of health behaviour interventions (including physical activity) based on the transtheoretical model (TTM) showed limited evidence for the utility of stage-based interventions as a basis for behaviour change or facilitating stage progression. The authors do acknowledge, however, that lack of evidence may be due in part to poor model specification, and the inappropriate manner in which interventions have been developed and delivered.

[2] Group equivalency between the three treatment conditions on the demographic factors also was found for the “non-exercise” (n = 72) subgroup.

[3] For the “non-exercise” subgroup, relations found among the demographic variables, PMT variables, exercise intentions, and exercise behaviour parallel those reported for the entire sample (N = 173).