Explaining the effects of a decision intervention on mammography intentions: The roles of worry, fear and perceived susceptibility to breast cancer

Abstract

Objective: This study examines the effects of a mammography decision intervention on perceived susceptibility to breast cancer (PSBC) and emotion and investigates how these outcomes predict mammography intentions.

Design: Randomised between-subjects online experiment. Participants were stratified into two levels of risk. Within each stratum, conditions included a basic information condition and six decision intervention conditions that included personalised risk estimates and varied according to a 2 (amount of information: brief vs. extended) × 3 (format: expository vs. untailored exemplar vs. tailored exemplar) design. Participants included 2465 US women ages 35–49.

Main Outcome Measures: PSBC as a percentage, PSBC as a frequency, worry, fear and mammography intentions.

Results: The intervention resulted in significant reductions in PSBC as a percentage for women in both strata and significant increases in worry and fear for women in the upper risk stratum. Of the possible mediators examined, only PSBC as a percentage was a consistent mediator of the effect of the intervention on mammography intentions.

Conclusion: The results provide insight into the mechanism of action of the intervention by showing that PSBC mediated the effects of the intervention on mammography intentions.

Keywords:

• perceived susceptibility
• perceived risk
• mammography
• decision aid
• worry
• fear

Notes

1. The 10-year breast cancer risk threshold of 1.5% was chosen to reflect the 90th percentile of 10-year risk for 50-year-old women (omitting the 10% with the highest risk, see Seitz et al., 2016). This would represent a somewhat elevated risk for a woman between the ages of 35 and 49 (i.e. our study population), and women with an elevated risk may benefit more from mammography in their 40s than women with a lower risk.

2. The experiment also included a no information comparison condition; however, because participants in that condition were not able to complete emotion measures (which required participants to report emotions experienced while reading the decision intervention), the no information comparison condition is not included in the analyses reported here.

3. A significant association between condition and the outcome variable was not a pre-requisite for testing for indirect effects, as Hayes (2013), MacKinnon (2008), and other scholars have recognised that indirect effects can exist in the absence of a significant correlation between X and Y.