We propose an Epidemiology and Biostatistics Core that will make available to CCMBM investigators data from a large number of studies that are supported by NIAMS and other sources. These studies include clinical data, images, and biological samples on over 100,000 men and women followed for over 1,000,000 person years. The Core currently receives about $20,000,000 per year in total costs for bone and joint projects of which about 60% in from NIAMS. The EB Core would also provide consulting on study design and biostatistics and education of design and implementation of clinical research projects. The specific aims of the Core are as follows: 1). To make available to the UCSF osteoporosis and osteoarthritis research community large, longitudinal databases including associated biological and imaging data that will be used to test hypotheses and techniques regarding the pathogenesis, risk factors, and diagnosis of osteoporosis and osteoarthritis. 2). To train UCSF bone and joint researchers in good study design and execution practices to maximize the rigor and validity of their work. 3). To provide data analysis services and consultation for genetics and genomics data sets. 4). To provide to the CCMBM community at UCSF consulting in the design and analysis of NIH-funded projects and proposals as well as pilot studies funded by CCMBM. 5). To encourage stronger ties and to serve as a conduit for collaborations between basic, translational, and clinical research in bone and joints at UCSF. The Core will be Co-Directed by Dennis Black, PhD and Michael Nevitt, PhD, and will build on existing collaborations with CCMBM members, (e.g. radiology, orthopaedic surgery, and endocrinology) to design new studies that enhance the value of existing NIAMS fund resources. The proposed CCMBM will have high clinical impact by stimulating collaborations between basic and clinical scientists that would not otherwise exist. This is an exciting and unique opportunity to leverage the vast osteoporosis and osteoarthritis resources, at UCSF to address new questions and expand the bone and joint research community.