ABSTRACT
Medical care received at end-of-life is often not aligned with individuals' values and care preferences. Much can get in the way of an individual communicating and documenting their preferences to care providers and close others, even if it is a goal to do so. The objective of this work was to develop a measure of Advance Care Planning Self-Efficacy (ACP SE) focused on three important behaviors: completing a living will, documenting a healthcare agent, and discussing quality versus quantity of life issues. Measure development was framed by the Transtheoretical Model (TTM) of behavior change. Following the completion of focus groups and formative qualitative work, an independent sample (N = 310, adults aged 50+) was randomly split into two halves for exploratory and confirmatory factor analyses (EFA/CFA). Multivariate analyses examined relationships between ACP SE and other TTM constructs. Results of the CFA demonstrated excellent internal consistency (α = .95) and good model fit (CFI = .89, RMSEA = .13). Self-efficacy was framed by the TTM as situation-specific confidence. Through the measure development process, it was found that confidence to do ACP was impacted by various situational and attitudinal variables. ACP Self-Efficacy was found to differ significantly by Stage of Change. This study produced a reliable and valid measure of situation-specific confidence for ACP grounded within the TTM that could enhance future interventions aimed at increasing participation in ACP.