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Study Description

The Osteoarthritis Initiative (OAI) is a publicly and privately funded prospective longitudinal cohort with a primary objective of identifying risk factors for incidence and progression of tibiofemoral knee OA. The OAI utilized a focused population-based recruitment to enroll 4,674 men and women between the ages of 45-79 years who either had radiographic symptomatic knee OA or who were without radiographic symptomatic OA in both knees but were considered high risk for OA because they had two or more known risk factors for knee OA. Subjects were recruited into the baseline phase of the OAI at multiple sites throughout the US between 2004 and 2006. All subjects were invited back for follow-up examinations to assess incidence or progression of OA annually, for up to 5 years.

Phenotype data from the baseline and follow-up examinations are available for public access from the Osteoarthritis Initiative (OAI) database at http://www.oai.ucsf.edu/.

The Genetic Components of Knee Osteoarthritis (GeCKO) Study was initiated in 2009 as a genetic ancillary study to perform a genome-wide association study to identify genetic variants associated with radiographic osteoarthritis. This study included 4,482 individuals participating in the parent OAI study. Following sample cleaning (e.g., removal of duplicates, sex mismatches, poor sample quality, etc.), the final sample set included 4,129 individuals.

  • Study Weblinks:
  • Study Type:
    • Longitudinal
  • dbGaP estimated ancestry using GRAF-pop
  • Number of study subjects that have individual-level data available through Authorized Access:
Authorized Access
Publicly Available Data (Public ftp)

Connect to the public download site. The site contains release notes and manifests. The site also contains data dictionaries, variable summaries, documents, and truncated analyses, whenever available.

Study Inclusion/Exclusion Criteria

Men and women between the ages of 45-79 years with either 1) radiographic symptomatic knee OA defined as having both a) pain, aching, or stiffness on most days of one or more months during the past year; and b) a definite tibiofemoral osteophyte (OARSI grade 1 or greater) from at least one knee (progression cohort); or 2) a high risk cohort defined as having no symptomatic radiographic knee OA in either knee but with known risk factors for knee OA (incident cohort). Eligibility criteria for the high risk cohort required that participants must have two or more risk factors for inclusion (i.e., overweight [using gender and age-specific cutpoints]; age 70 or older; history of knee injury causing difficulty walking for ≥ 1 week; history of knee surgery; total knee replacement for OA in a biologic parent or sibling; bony enlargement of one or more distal interphalangeal joints in each hand (confirmed by exam); current daily activities requiring frequent stooping, bending, lifting, squatting, and kneeling; and knee symptoms that do not meet the threshold for "most days" of a month.)

Molecular Data
TypeSourcePlatformNumber of Oligos/SNPsSNP Batch IdComment
Whole Genome Genotyping Illumina HumanOmni2.5-4v1_B 2450000 1056550 hg37
Study History

Name of grants: combination of public and private funding (see http://oai.epi-ucsf.org/datarelease/funding.asp)

Name of grants: Genome-wide Association Study to Identify Genetic Components of Knee OA: The OA
Agency number: NIH/NIAMS, RC2 AR058950
PI: Rebecca D. Jackson, MD
Dates: 09/29/2009-08/31/2011
Specific aims: The goal of this project is to perform a genome-wide association study to identify genetic variants associated with radiographic osteoarthritis.

Selected publications
Diseases/Traits Related to Study (MeSH terms)
Links to Related Resources
Authorized Data Access Requests
Study Attribution