PROJECT ABSTRACT The purpose of this K23 career development award is to support Dr. Ackenbom's long term career goal of becoming an independent surgeon-scientist advancing knowledge on cognitive impairment after surgery used to improve surgical outcomes and quality of life for older patients. Recognizing postoperative neurocognitive disorder (pNCD), previously termed postoperative cognitive dysfunction (POCD), in surgical patients is essential as it is associated with delayed postoperative recovery, greater loss of independence, increased morbidity, mortality, and substantial health care costs. In the United States, approximately 35% of all surgeries are performed on adults ≥65 years, and with the increase in the aging population, the number of surgeries and thus pNCD incidence is expected to rise. pNCD/POCD is characterized as a largely transient deterioration of concentration, information processing, and memory often lasting days to months, but there are studies reporting cognitive impairment after surgery lasting years. Cognitive impairment occurring more than 12 months after surgery is concerning for an ongoing diagnosis of mild cognitive impairment or other cognitive diagnoses, inclusive of Alzheimer's disease and related dementias (ADRD).There is a critical research need to examine the longitudinal course of cognitive impairment after surgery and its influence on everyday functioning, independence, and quality of life as it is not well understood. We propose a study using linked 2011-2017 data from the National Health and Aging Trends Study (NHATS), a population-based study focused on late-life functioning over time, with Medicare claims data, inclusive of surgical data variables as well as building upon a surgical patient cohort with available detailed neuropsychological testing results to address the following aims: 1) compare change in cognitive performance of persons ≥65 years who underwent major noncardiac elective surgery and those who did not, 2) compare change in everyday functioning in persons ≥65 years who underwent major noncardiac elective surgery and those who did not, 3) assess change in cognitive performance and diagnosis two years after prolapse surgery in women ≥70 years previously enrolled in Ackenbom et. al study assessing pNCD. The training aims in this proposal are: 1) To build on foundational knowledge in measurement of a range of cognitive abilities in clinical research settings and 2) To enhance my knowledge and understanding in research and clinical diagnosis and management of cognitive impairment disorders in general and in particular, ADRD, to incorporate into future study designs involving cognitive evaluation in perioperative settings. This study will determine appropriate effect sizes in preparation for future studies to conduct an extended assessment of cognitive performance and cognitive diagnoses, including pNCD and incident dementia, after undergoing major noncardiac elective surgery in persons ≥70 years ov...