Abstract / Summary
Importance: In the Melanoma Genomics Managing Your Risk Study, receiving personal genomic risk testing led to improvements in some melanoma prevention and early detection behaviors.
Objective: We aimed to examine the hypothesized psychosocial mediators of the effects observed in the trial.
Design: Australians of European ancestry without melanoma and aged 18-69 years were recruited via the national Medicare database and randomized to receive personal genomic risk information or usual care (N = 1025). Questionnaires were administered at baseline, 1-month post-intervention, and 12-months post-baseline to assess self-reported prevention and early detection behaviors and psychosocial measures. We first evaluated the intervention's effect on psychosocial measures and the associations between psychosocial measures and behavioral outcomes. We then estimated the natural indirect effects (NIEs) and their 95% confidence intervals (CIs) to quantify the effects mediated by potential mediators identified.
Results: Among participants with high traditional melanoma risk, the intervention's effect on increased sun protection at 1 month was partially mediated by changes in the perceived importance (NIE mean difference 0.02; 95% CI: 0.00-0.04) and perceived effectiveness (0.01; 0.00-0.03]) of sun protection strategies. Among women, the intervention's effect on increased whole-body skin examinations at 1 month was partially mediated by perceived capability to engage in skin examinations (NIE odds ratio 1.08; 95% CI: 1.00-1.29) and perceived control over detecting a future melanoma (1.13; 1.03-1.32).
Conclusions and relevance: The effectiveness of precision prevention and early detection interventions may be enhanced by targeting key psychosocial mediators through tailored communication of personal melanoma risk.