The Osteoarthritis Initiative: Update on a NIH Public-Private Partnership

Updated January 7, 2013

Osteoarthritis affects more than 27 million individuals in the United States1. The NIH has long supported research to improve outcomes for patients with this debilitating disease. Knee osteoarthritis is associated with significant pain and development of disability over time. People who are severely compromised have few effective treatment options other than joint replacement. It has been noted that there are differences in the prevalence, incidence and severity of osteoarthritis between men and women and among races. There currently are no disease-modifying agents for the treatment of osteoarthritis. The discovery of osteoarthritis biomarkers—including structural characteristics that can be observed with MRI—could lead to identification of new treatment targets and mechanisms for shorter, more efficient trials of disease-modifying agents.

The Osteoarthritis Initiative (OAI) is a multicenter, longitudinal, prospective observational study of knee osteoarthritis (OA) that was launched by NIH in 2002. The overall aim of the OAI is to develop a public-domain research resource to facilitate the scientific evaluation of biomarkers for osteoarthritis as potential surrogate endpoints for disease onset and progression. The goals of the OAI were to enroll approximately 5,000 subjects with risk factors for or early knee osteoarthritis and to collect clinical and imaging data and biological specimens from these participants for originally four, and now eight years of follow up. No details are provided here with regard to study start-up, protocol development, or recruitment and enrollment. Overviews are available on the NIAMS website (; technical details are available on the OAI website

Funding for the OAI has been contributed by both NIH and private sector participants. The private sector funding was initially provided from Pfizer, Merck, GlaxoSmithKline, and Novartis. The Foundation for the National Institutes of Health (FNIH) has coordinated private sector participation. Funding from the NIH institutes and centers initially included NIAMS, the National Institute on Aging (NIA), the National Center for Complementary and Alternative Medicine (NCCAM), the National Center on Minority Health and Health Disparities (NCMHD), the National Institute of Dental and Craniofacial Research (NIDCR), the NIH Office of Research on Women’s Health (ORWH), and the National Institute for Biomedical Imaging and Bioengineering (NIBIB). Financial support for the extension of follow up for the OAI cohort (additional four contacts, 2010-2014) has been provided by Pfizer and Novartis from the private sector and the NIAMS, NIA, NCCAM, NCMHD, ORWH, and NIBIB.

The OAI research team consists of the following centers and their principal investigators: University of Maryland School of Medicine, Baltimore: Marc Hochberg, M.D., M.P.H.; The Ohio State University, Columbus: Rebecca Jackson, M.D.; University of Pittsburgh: C. Kent Kwoh, M.D.; Memorial Hospital of Rhode Island, Pawtucket: Charles Eaton, M.D.; University of California, San Francisco (data coordinating center): Michael Nevitt, Ph.D. A Steering Committee, comprised of representatives from these centers, the NIH, and the pharmaceutical partners, advises on the scientific aspects of the study. The U.S. Food and Drug Administration provides a representative to serve as a liaison to the Steering Committee in an advisory manner.

The OAI cohort of 4,796 subjects is 58% female and ranged in age from 45-79 at time of recruitment. As of early 2011, the entire OAI cohort has completed their baseline, 12-month, 24-month, 36-month, and 48-month visits. The 60-month visit is by telephone and is approximately 95% complete. The 72-month visits are in-clinic and well underway at all sites (48% of cohort has completed). The 84-month telephone and mail visits have begun in two of the clinics and will begin in the other two clinics in the next several months. Planning is underway for the 96-month in-clinic visits to begin in 2012. A subset of participants in the progression cohort were also seen at 18 months (n=288) or 30 months (n=494) for knee MRI, blood draw, exam and questionnaire data to allow for analysis of change over shorter intervals; these data are already posted on the OAI website. Retention remains high, although some participants (~7%) from the original cohort did not continue for the additional four years of follow up. The rate of no-contact has stabilized in the 15-18% range.

There are four separately NIH funded (R01 and R21 mechanisms) ancillary studies to the OAI, which are well underway. One of the most recent ancillary studies addresses the effects of physical activity on disability progression. Physical activity is measured using an accelerometer to see whether participants who meet the recommended activity guidelines can slow disability progression. Additionally, in 2010, the NIAMS funded three contracts for analysis of OAI data to Dr. Charles Eaton at Memorial Hospital of Rhode Island, for "Osteoarthritis Patient-centered Outcomes and Complementary and Alternative Therapy (CAM)"; to Dr. C. Kent Kwoh at University of Pittsburgh, for "Pivotal Osteoarthritis Initiative Magnetic Resonance Imaging Analyses"; and to Dr. Michael Nevitt at University of California, San Francisco, for "Hip Morphology and Limb-specific Risk Factors for Radiographic Hip Osteoarthritis."

Data are released on a regular basis to OAI Online. As of January 2013, there were 2,583 registered users of OAI Online from 100 countries, with over 13,686 datasets downloaded and 587 image sets distributed. Data are currently being released in a single bolus for the entire visit. Recent releases have included the 60-month questionnaire data. Clinical data and images from baseline to 48-month visits are currently available for use. An increasing number of abstracts and papers are being produced based on use of the OAI data and images (see

This groundbreaking study is expected to advance our understanding of how modifiable and non-modifiable risk factors are linked to development and worsening of knee osteoarthritis. These findings may, in turn, lead to improved strategies for prevention of disease, identification of novel treatment targets and ways to prevent later-life disability.

1 Prevalence of knee osteoarthritis in the United States: arthritis data from the Third National Health and Nutrition Examination Survey 1991-94. Dillon CF, Rasch EK, Gu Q, Hirsch R. J Rheumatol. 2006 Nov;33(11):2271-9. Epub 2006 Oct 1. PMID: 17013996