Medicare beneficiaries ≥65 years old who are at risk for incident or recurrent cardiovascular events often have physiologic problems affecting multiple organ systems, which can lead to receiving ambulatory care from providers in different specialties. Although receiving care from multiple providers may be clinically appropriate, gaps in communication among providers are common, which can be hazardous for patients. Accountable care organizations (ACOs) often employ “care coordinators” (typically with backgrounds in nursing or social work) who facilitate communication among the individuals involved in a patient’s care. However, ACOs typically have thousands of patients and only a few care coordinators. How to optimally allocate care coordinators is not known. The usual approach has been to assign care coordinators to patients after a hospital discharge. While this is reasonable, it assumes that all discharged patients need care coordination (which they may not), and it has the disadvantage of waiting until after a hospitalization has occurred. Meanwhile, patients are often aware of when their care is not being well coordinated, yet no existing intervention leverages these observations. A pilot randomized controlled trial will determine the comparative effectiveness of two approaches for assigning care coordinators to patients: (a) a novel patient-centered approach that assigns care coordinators to those who perceive a problem with care coordination vs. (b) usual care (i.e., after hospital discharge). The Research Aims are to: (1) determine the comparative effectiveness of these two approaches on the combined outcome of emergency department visit or hospitalization over 12 months of follow-up, and (2) measure implementation outcomes (acceptability, appropriateness, fidelity, and efficiency) to inform a future multi-center randomized controlled trial. The pilot trial will include Medicare beneficiaries ≥65 years old (N = 400 total, or 200 per trial arm) who are attributed to an ACO, have cardiovascular disease or ≥1 cardiovascular risk factors, and had highly fragmented ambulatory care in the past year (as a risk factor for gaps in communication). Lisa Kern, MD, MPH (PI) is an Associate Professor of Medicine and health services researcher who is expert in ambulatory care quality and who has spent her career to date conducting independent evaluations of others’ interventions and observational studies of her own. This K18 AHRQ Mentored Career Enhancement Award for Established Investigators in Patient-Centered Outcomes Research would allow Dr. Kern to transition to a career of designing, implementing, and evaluating her own interventions, through learning pragmatic clinical trials (Training Aim 1) and implementation science (Training Aim 2). Dr. Kern’s mentoring team has expertise in pragmatic clinical trials, implementation science, care coordination, cardiovascular disease, and biostatistics. The proposed work has the potential to improve ambulatory c...