Use of theory to develop a decision aid for parents whose daughters face cancer-related threats to fertility

Background: Although the development and use of decision aids has increased over the last several decades, many have not been designed based upon a theoretical framework. Fertility preservation decisions may be made by the parent(s), with or without the child's input. Therefore, it is crucial to consider a combination of theories from various disciplines that take into account cognitive and affective components of decision making, as well as family dynamics. Design and Methods: A sample of parents of girls who have been treated for cancer have been interviewed (n=6) regarding their decision making about fertility preservation. Analysis of transcripts allows for the development of a preliminary model based on the Theory of Planned Behavior, Family Systems Theory, Cognitive Load Theory, and Shared Decision Making to guide the development of a decision aid for this population. Results: Limitations of each model have been identified. For example, central to the Theory of Planned Behavior is the construct of Perceived Behavioral Control: one's perceptions of his or her ability to perform a given behavior. In this context, the parent(s) control the decisions made on the child's behalf. Choosing *not* to act, i.e., rejecting experimental treatments to preserve fertility, may be construed as removing a child's *future* behavioral control. We will incorporate additional theoretical constructs such as cognitive load, values clarification, and equifinality. Conclusions: We will present a combined framework based on interviews with parents that can be applied to decisions in several contexts of proxy decision making.