Project Summary/Abstract (30 lines max) Our project, R01AG067507: “Understanding and Improving Surgical Decision-Making for Persons Living with Dementia, their Family Caregivers, and their Providers: A Mixed Methods Study”, has made great progress toward our goals. As per the criteria of PA-20-272, this proposed work will "increase and preserve the parent award’s overall impact " by "achieving certain new research objectives… within the original scope of the peer reviewed and approved project." We have identified four areas of investigation that would benefit from supplemental funding: 1) The need for evidence on outcomes for surgeries in addition to ones specified in the original project. 2) The need to investigate surgery taking place in outpatient settings including Ambulatory Surgery Centers. 3) The need to investigate medical (non-surgical) alternatives for patients who are eligible for surgery yet prefer not to proceed. 4) The need to examine longer term outcomes, such as 4-5 year survival, with more current data. We therefore propose to supplement our current project to understand the epidemiology of surgery for PLWDs, as well as patient, caregiver, and provider practices and challenges of surgical decision-making in clinical settings. Supplemental Aim 1) Develop the evidence base to understand comparative outcomes of surgery provided to PLWDs. We will use Medicare data to: 1) describe the epidemiology of surgery for PLWDs for selected elective major cancer (e.g., breast cancer) and non-cancer surgery (e.g., colectomy for benign conditions, cholecystectomy), and analyze the association of dementia status with outcomes, including 5 year survival and Excess Days in Acute Care (EDAC); 2) Compare outcomes among alternative surgical interventions; and 3) Track outcomes for patients with and without surgery. Supplemental Aim 2) Characterize surgical decision-making for PLWDs in clinical settings for the surgical situations described in Supplemental Aim 1. Supplemental Aim 3) We will supplement our modified Delphi panel to consider the situations described in Supplemental Aim 1. Impact. Results of this supplemental work will greatly increase the impact of the current project using the currently funded research infrastructure. Our study will support key advancements in ADRD research by focusing on under-studied areas of surgical decision-making. Our Aims are linked but not conditional, and results from Aims 1 and 2 will inform the Delphi panel. Our work also will address other NIH research priorities including barriers faced by vulnerable populations, goals of care, and better decision-making.