Abstract 968: Predictors of advance care planning documentation in female patients with breast cancer: A multilevel model analysis

Abstract Background: Advance care planning (ACP) is a process that supports adults at any age or stage of health in understanding and sharing their personal values, life goals, and preferences regarding future medical care. Likewise, ACP is associated with multiple benefits, such as lower rates of hospitalizations and reduced futile, aggressive cancer treatment at the end of life. However, ACP rates remain low in the U.S., especially for patients with advanced cancer. Despite being more likely to be diagnosed at advanced stages and hospitalized due to advanced cancer with poor prognosis, Black and Hispanic/Latino populations continue to have very low rates of ACP. Research has shown that both individual-level and systems-level factors contribute to these racial disparities in ACP. Considering these disparities among vulnerable populations, interventions that increase ACP among minority patients with cancer are needed. Objective: To analyze using multilevel model analysis the predictors of ACP documentation in female patients with breast cancer over 5 years in the UChicago Health System. Methods: Using the Clinical Data Research Warehouse, this study included women diagnosed with breast cancer (N=7,814) from 2016 to 2021. Descriptive statistics were performed to characterize ACP, and potential differences in ACP rates among control variables were assessed using odds ratio (OR) estimations. Analyses were conducted using random effects (mixed effects) multilevel modeling. To account for individual differences in ACP documentation completeness over time, both intercept and slope were included as random effects. In the multilevel model, level 1 modeled individual ACP documentation and level 2 tested the group effects in ACP documentation. The effect of time was tested in level 1, and the variances in the intercept and slopes were represented in level 2. Results: 8.74% of women with breast cancer had at least one type of ACP documented in their medical records; 4.25% had a power of attorney and 5.75% had an advanced directive. Age and the time elapsed between diagnosis and ACP completion are related to an increased likelihood of ACP completion over time. Being divorced increased the likelihood of ACP completion at baseline. Outpatient services decreased the likelihood of ACP completion over time. Conclusion: Understanding the factors that are related to ACP documentation will allow us to manage them and improve their completion. These results will help to inform the development of tools to increase the integration of ACP into care, especially those that are technology-based. Further work could include the design of a predictive model to prioritize patients who require ACP. Providing knowledge about ACP in nonclinical areas can lead to increased education about ACP and its benefits to families and communities. Citation Format: Andres Mauricio Garcia Sierra, Marcia Tan. Predictors of advance care planning documentation in female patients with breast cancer: A multilevel model analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 968.