On June 15, 2010, three organizations were selected to receive contract awards under Broad Agency Announcement (BAA) NHLBI-AR-10-06, Ancillary and Complementary Research to the Osteoarthritis Initiative (OAI). The contract awards were made to Memorial Hospital of Rhode Island, Charles B. Eaton, PI; University of California San Francisco, Michael Nevitt, PI; and University of Pittsburgh, C. Kent Kwoh, PI. The purpose of the BAA was to maximize scientific yield from the biologic resource, images, and the associated participant exposure and outcome data created through the Osteoarthritis Initiative (OAI) by the solicitation of research studies that used the OAI resource. The overall OAI program is intended to provide a research resource for the discovery of biomarkers and potential treatment targets for knee osteoarthritis. The Broad Agency Announcement offered opportunities in support of the use of the OAI resources to expand knowledge in these and other areas. The applicants were requested to address one or more of the following areas: 1. Development of tools and resources to maximize public access to and use of the OAI database and image repository; 2. Development of novel and efficient tools for analysis of MR images and x rays that can be applied to large numbers of images with high degrees of reproducibility for diagnosis and monitoring of OA-related changes; 3. Identification and validation of risk factors for knee and hip OA including both modifiable and non-modifiable risk factors; 4. Determination of predictive role of MRI changes for subsequent radiographic and clinical outcome changes related to development of knee OA; 5. Analyses of efficacy of biobehavioral, pharmacological, and 'natural' interventions (including pain meds, over the counter, CAM, aids, vitamins, etc) that subjects use in response to OA pain. (Based on data already collected from the OAI); or 6. Research focused on the trajectory of disease including effects on other joint structures such as muscles, ligaments, and bone, with regard to points where interventions could be made, especially for subsets, to reduce OA severity.