Multicenter Osteoarthritis Study Overview and Objectives
Osteoarthritis (OA) is the most common form of arthritis and the major cause of activity limitation and physical disability in older people. More than half
of those over the age of 65 have radiological evidence of osteoarthritis in at least one joint. By 2030, approximately 20 percent of Americans (about 70 million people)
will have passed their 65th birthday and will be at increased risk for the disease. Today, 39 million people (13 percent of the U.S. population) are 65 and older,
and more than half have developed OA.
The Multicenter Osteoarthritis Study (MOST) is a longitudinal, prospective, observational study of knee OA in older Americans with OA disease or at increased risk of developing it.
The study is comprised of two clinical centers, a data coordinating center, and an analysis center.
MOST enrolled 3,026 study participants and has conducted five follow-up contacts at 15, 30, 60, 72, and 84 months. At each time point, clinical assessments were conducted
and radiological data (x-ray and MRI) collected, as well as other measures and instruments, with the exception of the 72-month follow-up, which was a Telephone Interview only.
The overall aims of MOST are to identify novel and modifiable biomechanical factors (including physical activity-related factors), bone and joint structural factors
(including those assessed by MRI of the knee), and nutritional factors that affect the occurrence and progression of OA-related knee symptoms and radiographic knee OA.
Additionally, MOST investigators aim to determine whether risk factors for new disease differ from those for OA progression.
The MOST cohort has been followed through 84 months with three investigative themes: mechanical risk factors, causes of knee symptoms and pain,
and the long term disease trajectory of knee OA.
To achieve these aims, we recruited a community-based sample of 3,026 (101% of our goal) men and women aged 50 to 79 and drawn from the general population but selected so as to be
likely to either have preexisting OA or be at high risk as indicated by weight, knee symptoms, or a history of knee injuries or operations. Approximately 15% of the cohort are
African Americans and 60% are women. Baseline exams began in 2003 and included an assessment of risk factors and disease characteristics, knee radiographs and knee MRIs, and a
musculoskeletal examination to identify knee symptoms that do not emanate from the knee or hip joint. Knee MRIs were acquired with a 1.0 T dedicated extremity MR scanner (GE Healthcare).
MOST participant retention is excellent, as summarized in the tables below.
Retention success in MOST: Follow-up Data Collected by Time Point, Gender, and Racial Background