Abstract Previous studies examining decision making in the context of genetic testing for BRCA1/2 gene mutations have been limited in their reliance on cross-sectional designs, lack of theoretical guidance, and focus on measures of intention rather than actual behavior. Informed by the Health Belief Model and other theories of self-regulation, the present study set out to examine the role of cognitive appraisal and worry in BRCA1/2 testing decisions. A total of 205 women completed baseline questionnaires prior to their genetic counselling appointment. Medical charts were audited to determine testing decisions. Bivariate analyses indicated that perceived severity of being a carrier and perceived benefits and barriers to testing were significantly associated with testing decisions. Perceived benefits remained significant in multivariate analyses. Moreover, multivariate analyses revealed a significant three-way interaction between perceived susceptibility, perceived severity, and worry about being a mutation carrier and testing decisions. Among women high in baseline worry, those high in perceived susceptibility but low in perceived severity were significantly more likely to undergo genetic testing than all other susceptibility/severity combinations (80% vs. 36.2-42.9% range; Wald test ¼ 8.79, p < 0.01). These results support the need for researchers and practitioners to consider how interactions between cognition and worry may influence genetic testing decisions
