ABSTRACT ? RESOURCE CORE The overall goal of the UNC CCCR is to enhance the design and conduct of clinical studies in Rheumatic and Musculoskeletal Diseases (RMDs) with a focus on osteoarthritis (OA), a particular strength of our research community. The Phenotyping and Precision Medicine Resource Core will provide critical services to our research community that broadly include: 1) key scientific expertise and analytic resources needed for prognostic phenotyping (predicting outcomes by specific subgroups, e.g. ?progressors? versus ?non-progressors?) and prescriptive phenotyping (predicting response to specific interventions) using clinical datasets, and 2) guidance and advice to investigators on phenotypic considerations (such as choice of input and outcome variables) in order to enhance the design, implementation, and interpretation of new clinical studies and trials. Like many chronic conditions, RMDs, including OA, are not single diseases but rather heterogeneous conditions consisting of multiple phenotypes that differ in their underlying pathobiological mechanisms. If not taken into consideration, these differences result in the testing of interventions designed to address specific mechanisms of action in the ?wrong? patients. Successful treatments for RMDs therefore need to be targeted to, and tested in, specific subgroups or subtypes that share distinct underlying pathobiological, psychosocial and pain mechanisms, consistent with the goal of precision medicine. The Phenotyping and Precision Medicine Resource Core will work in conjunction with the Methodology Core to provide services that will greatly enhance study design and add value to a wide spectrum of ongoing, completed, and planned clinical studies through the following aims: Aim 1. Provide consultative advice and analytical services for prognostic and prescriptive phenotyping for investigators interested in defining subgroups within new or ongoing clinical studies in OA or other RMDs, including ancillary studies and studies in the planning stages. Aim 2. Apply innovative strategies for phenotyping and precision medicine by leveraging data collected in selected clinical studies from our research community, adding value to those studies, facilitating external validation and informing future studies. Aim 3. Encourage broader implementation of phenotyping and precision medicine approaches for RMDs through education and dissemination of the methodologies to local, national, and international research communities. A resource core dedicated to phenotyping and precision medicine will greatly benefit the research community that will be supported by the CCCR, make a significant impact on the field of clinical RMD research, and ultimately on the lives of people suffering from these chronic and disabling conditions.