PROJECT SUMMARY/ABSTRACT Patients with chronic illness who develop acute respiratory failure face significant morbidity and mortality, with survivors often suffering serious physical and psychological sequelae. These patients have a critical need for palliative care. Palliative care is focused on improving quality of life for both patients and family of patients with serious illness by providing high-quality communication, symptom control, and emotional and spiritual support. Despite how important this type of care is, there is little information available regarding the quality of palliative care provided to chronically ill patients with acute respiratory failure. Without this knowledge, it is extremely challenging to develop effective interventions to enhance patient- and family-centered outcomes for this population. To fill this key knowledge gap, I will use explicitly defined, measurable items that detail the processes, outcomes, and structure of palliative care to achieve my primary objective of examining temporal trends in palliative care over the last decade, including an assessment of changes that have occurred since the inception of the COVID-19 pandemic. I have identified a cohort of over 16,000 patients with chronic, life-limiting illness hospitalized with acute respiratory failure between 2012 and 2022. Using this cohort, I will achieve my primary objective through two specific aims. Aim 1 will examine temporal trends in quality indicators of palliative care for patients with chronic illness hospitalized with acute respiratory failure between 2012-2022. Aim 2 will assess differences in quality indicators of palliative care for patients with chronic illness hospitalized with acute respiratory failure, comparing patients with COVID-19 to those without COVID-19, between 2020- 2022. By accomplishing the proposed aims, I will identify improvement, stagnation, and decline in care over time in specific process and outcome metrics across multiple palliative care domains, highlighting significant changes occurring during the COVID-19 pandemic and identifying differences in quality indicators of palliative care for those with and without COVID-19. Results from the proposed project will inform my future research to describe mechanisms underlying these trends, with the goal of developing effective interventions to improve care delivery for adults with chronic, life-limiting illness and acute respiratory failure.