PROJECT SUMMARY/ABSTRACT Shared decision making (SDM) is a process in which patients and clinicians work together to understand the patient’s problematic situation and collaboratively develop a plan of care that makes intellectual, practical, and emotional sense as a response to the situation and the individuality of the person. The practice of SDM is widely promoted through clinical guidelines, organizational and governmental policies and initiatives, and is a feature of patient-centered care. A goal of SDM is to improve health and behavioral outcomes through enhancing patients’ participation in decision making, however it has proven hard to establish this impact, in part due to limitations in measuring SDM. Researchers currently do not have the measures they need to determine if, in any patient-clinician encounter, a SDM process was used to collaboratively deliberate and form a plan of care. The ability to determine the occurrence of SDM is highly limited by a lack of conceptual and operational clarity around SDM, narrow measurement frameworks, and limitations to existing observer and self-reported measures, particularly in the context of chronic multimorbidity. Therefore, in this three-year study, the team—comprising experts in SDM, measure development and validation, and user-centered design—propose to develop a theoretically based, expert-informed, user-tested, observer-based measure of SDM occurrence (“SDMo”) and to estimate its reliability and validity. Specifically, the objectives of this application are to develop a comprehensive set of items using existing literature and theory to capture observable processes and behaviors indicative of SDM (Aim 1); using candidate items derived from Aim 1, to deploy a user-centered design process to develop a usable and feasible measure of SDM occurrence through an iterative process of field testing and refinement of the SDMo measure on a previously collected corpus of video-recorded clinical encounters (Aim 2); and to estimate the reliability and validity of the SDMo measure (Aim 3). Completion of these three aims will result in a usable measure of SDM occurrence in clinical encounters with patients with chronic multimorbidity, estimates of the measure’s reliability and validity, and a user-tested Users’ Manual that will include a detailed explanation of each item, illustrations for its use, and a training procedure with video clips that will promote highly reliable use of the instrument by other researchers. In the long-term, the new measure, SDMo, will contribute to uncovering the real prevalence of SDM in the care of patients with multiple chronic health conditions and improve the quality and consistency of research on SDM in this priority population. Ultimately, a comprehensive, valid, and reliable measure of SDM will allow clinical researchers to rigorously test associations between the practice of SDM and behavioral and physical health outcomes and facilitate improvements to clinical practice ba...