Table 1 Eligibility Criteria

• Age ± 50 years old

• Pain for at least 3 months duration

• Mild to moderate severity on the WOMAC pain scale

• Radiographic evidence of knee or hip OA

• Community-living (i.e, own home, senior residence, apartment)

• Adequate cognitive status (score of > 5 on the 6-Item Screener)[66]

• Ambulatory either with or without an assistive device

• Reliable operation of the Actiwatch-Score accelerometer

• English-speaking

Exclusion Criteria

• Medical conditions that may interfere with pain and fatigue reporting or activity monitoring (multiple sclerosis, lupus, rheumatoid arthritis, Parkinson's disease, peripheral neuropathy)

• Cancer diagnosis in the last year (other than skin cancer) or currently undergoing treatment for cancer

• Medicine changes within last 2 weeks

• Anemia or unmanaged thyroid dysfunction (from blood work result)

• 2 or more days of complete bed rest within last month

• Limb hemiplegia or amputation

• Knee arthroscopic procedure within the last 2 months

• Replacement of any hip or knee within the last 6 months

• Knee joint injection within the last 3 months

• Current receipt of physical or occupational therapy for OA symptoms or knee/hip problems

• Current attendance or attendance in the past 12 months in a cognitive behavioral program or other self-management program that includes activity pacing instruction.