PROJECT SUMMARY/ABSTRACT Dr. Devika Nair is an Assistant Professor of Medicine in the Division of Nephrology at Vanderbilt University Medical Center. With this K23, she will advance the precision, personalization, and scalability of behavioral interventions for older adults with chronic kidney disease (CKD) by developing and iteratively refining a novel, multicomponent, adaptive behavioral intervention able to be dosed in real-time. Dr. Nair will gain 1) new proficiency in behavioral science research, including analyzing cohort data containing patient-reported assessments, recruiting and retaining a new, longitudinal cohort, and developing adaptive behavioral interventions; 2) new knowledge in areas of geriatrics relevant to CKD (cognition and physical function); and 3) new competency in implementation science and mixed-methods design. An invested, integrated, and established team will support Dr. Nair's transition to independence. Dr. Kerri Cavanaugh will provide instruction in behavioral science. Dr. Warren Taylor will provide instruction in geriatrics and experiential learning in neurocognitive assessment. Dr. Daniel Cukor will provide instruction in behavioral interventions. Dr. Russell Rothman will provide instruction in implementation science. Dr. David Schlundt will provide guidance in mixed- methods design. Poor engagement in disease self-care behaviors (i.e., physical activity) leads to adverse cardiovascular events and death in older adults with CKD, the fastest growing kidney disease population. Existing interventions to improve self-care behaviors in this group are `one-size-fits-all' and do not result in durable behavior change due to inadequate tailoring and dose adjustment. Patient Activation, a modifiable measure of self-efficacy, knowledge, problem-solving skill, and level of need for behavioral support, is under- investigated in CKD despite its inclusion in CKD legislative policy. Cognitive function, the neurobiological processes requisite of goal-directed behavior and problem-solving skill, is often impaired in CKD yet its impact on engagement in disease self-care behaviors is unknown. To elucidate neurobiological and behavioral mechanisms of self-care behaviors, identify new intervention targets, and develop a novel, adaptive behavioral intervention, Dr. Nair will 1) test whether self-efficacy, Patient Activation and cognitive function associate with frequency of engagement in CKD self-care behaviors; 2) define how Patient Activation levels and CKD self- care behaviors change over time to inform intervention dosing, amount of support, and frequency; 3) identify patients' behavioral goals and triggers for ineffective self-care to inform timing and intervention component selection; 4) identify patient preferences for behavioral monitoring frequency and intervention delivery mode; 5) identify barriers and facilitators to intervention implementation into the health system; and 6) iteratively refine the prototype with usability tes...