DESCRIPTION:  Recently, the terms “patient engagement” and “patient-centered” have been used extensively, but rarely defined or commonly understood in the context of health care and research. To involve patients in research and health care delivery with the goal of improving health outcomes important to them, users need to understand the full scope of patient engagement and to define the attributes of these terms. The Patient Engagement in Research Working Group conducted a systematic review to identify existing definitions used over the past 10 years for patient engagement and centeredness, and 14 other patient-related terms in the context of health care research and practice. The Working Group screened 1371 abstracts and reviewed full-text articles seeking definitions. This forum will allow the Working Group to present the results from the systematic review and the resulting analyses used to identify emergent themes. Preliminary results of definitions for patient-related terms in the scope of health economics and outcomes research will be presented for audience discussion.