"The Development of a Decision Aid to Promote Informed, Shared Decision Making for Contralateral Prophylactic Mastectomy (CPM)"

Contralateral prophylactic mastectomy (CPM) is a risk-reducing surgical removal of a healthy breast to reduce the risk of developing breast cancer. Although most women diagnosed with breast cancer will never develop a contralateral breast cancer, it continues to be an area of discussion at surgical consultation. The decision point of considering CPM versus unilateral mastectomy is a patient-sensitive decision that can benefit from ongoing, shared, decision-making interventions. Decision aids (DAs) are a feasible and acceptable approach to improve the shared, decision-making process in the clinical setting. Therefore, the aims of this dissertation are (1) to explore factors and values contributing to women choosing CPM versus unilateral mastectomy, and (2) to determine the content validity and final evaluation of the modified DecisionKEYS for CPM to provide content and feedback for the continued modification of the DecisionKEYS interventions.

In the first manuscript, following the Whitemore and Knafl (2005) proposed steps, an integrative review of current DAs for the choice of CPM versus unilateral mastectomy is presented. In the second manuscript, the multi-phase, mixed methodological approach for the study aims is outlined. Phase I, as presented in this dissertation, aims (1) to explore factors and values contributing to women choosing CPM versus unilateral mastectomy, and (2) to determine the content validity and final evaluation of the modified DecisionKEYS for CPM to provide content and feedback for the continued modification of the DecisionKEYS interventions. Phase II will address study aims (3) to compare pre-post levels of decision conflict and decision-making quality, and (4) to identify later decision regret based on choice type for women using DecisionKEYS over time when choosing CPM versus unilateral mastectomy.

In the third manuscript, a mixed method approach using semi-structured interviews and two quantitative surveys, the Decision Making Quality Scale (DMQS) and the Decision Regret Scale (DRS) is presented. Four themes were identified from the qualitative data: 1) fear of cancer recurrence or a cancer diagnosis in the opposite breast, 2) empowerment and self-trust, 3) previous experiences, histories, and influences related to cancer, and 4) expressed need for increased psychosocial support at the time of initial diagnosis. Quantitative findings indicate that participants rate their decision-making quality as high (DMQS scores were high) and did not report any later regret post-surgery (DRS scores were low).

In conclusion, a DA is feasible and acceptable in the clinical setting when patients are considering CPM versus unilateral mastectomy. Future research is also needed to test the modified version of DecisionKEYS for CPM as an intervention to improve shared decision making and compare levels of 1) decision conflict, 2) decision-making quality, 3) decision regret, and 4) risk tolerance.