PROJECT SUMMARY Postoperative delirium is among the most common complications following elective surgery. Delirium is associated with prolonged lengths of stay, functional decline, cognitive impairment, higher costs, and higher mortality. This proposal describes a career development plan that will transform Dr. Mohanty into a patient- oriented investigator focused on improving the perioperative brain health of every older American undergoing major surgery. Dr. Mohanty’s proposed project will involve merging the data of more than 35000 patients who underwent major surgery in a statewide health system with electronic health record (EHR) data from the Indiana Network for Patient Care (INPC), a Regional Health Information Exchange. Using this merged database, the candidate will develop and test a passive predictive model (“digital marker”) for postoperative delirium risk using routine care EHR data, including unstructured, free text notes, and a machine learning algorithm. This “digital marker” will then be tested in a pilot randomized clinical trial in preparation for a large efficacy trial which will evaluate the impact of this scalable “digital marker” on short and long-term cognitive outcomes. The proposed career development plan integrates: close mentoring from a multidisciplinary team of senior scientists; coursework and structured didactics in medical informatics, including advanced analytics, artificial intelligence, and clinical decision support; implementation science; experiential learning via the conduct of the proposed research project; and a supportive research environment. This environment includes an internationally recognized NIH-funded delirium study group, the distinguished Indiana University Center for Aging Research, the NIA-funded Indiana Alzheimer’s Disease Center, and the NIH-funded Indiana Clinical and Translational Sciences Institute (CTSI). This career development award will guarantee protected time that will be necessary to advance the candidate’s career in perioperative brain health. In addition, the award will provide critical support to collect data for a future R01 efficacy randomized controlled trial.