Understanding Advance Care Planning Among Young Adults: A Theory-Based Examination Using the Integrated Behavioral Model and Precaution Adoption Process Model

The advance care planning process (ACP) enables individuals to document medical preferences if they become unable to communicate. Despite benefits such as reduced stress for loved ones and improved end-of-life care, young adults typically remain under involved in the ACP process. This study examined predictors of ACP behaviors among U.S. adults aged 18-35 (N = 614) using the Integrated Behavioral Model (IBM) and the Precaution Adoption Process Model (PAPM). ACP engagement was defined as completing a living will, designating a durable power of attorney for health care (DPAHC), and discussing wishes with a loved one. Most participants (68.6%) had not fully engaged in ACP. Regression analyses revealed that direct perceived norms, attitudes, and life experience with serious illness were significant predictors of intention to engage in ACP. Younger respondents (18-25) reported stronger IBM construct scores despite lower engagement overall. Participants in PAPM stage 5 (intending to act) scored higher on attitudes, norms, self-efficacy, and intention than those in earlier stages. Personal or family experiences with life-threatening illness emerged as key motivators. Findings suggest theory-informed, stage-based interventions may enhance ACP engagement among young adults by addressing social norms, strengthening self-efficacy, and increasing knowledge through developmentally appropriate strategies.