Examination of the Dose Response Relationship Between Physical Activity and Arthritis-Attributable Outcomes

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

The majority of adults with arthritis in the United States do not meet the federal physical activity guidelines of 150-300 minutes/week of moderate-to-vigorous intensity physical activity (MVPA). Adults with arthritis face numerous barriers to engaging in regular MVPA and seek specific recommendations for activities from healthcare providers. A major gap remains in identifying the minimal dose of activity necessary to see clinical improvements in arthritis-related outcomes. Lower doses of activity could lead to improvements in arthritis- related symptoms and may be a more feasible, initial goal for adults with arthritis who have difficulty engaging in activity at the recommended levels. Further, shorter bouts of MVPA could result in fewer short-term negative effects on arthritis-related symptoms as compared to higher daily durations of activity. Therefore, the purpose of this study is to identify whether a dose-response relationship exists between objectively-measured MVPA and arthritis-attributable outcomes in adults with arthritis. The first aim is to examine the effect of 3 doses of MVPA (45 min/week, 90 min/week, and 150 min/week) on arthritis-attributable outcomes (e.g., physical function, health-related quality of life, pain, and depression symptoms) in adults with arthritis at 6 and 12 months. The second aim is to examine the between-group differences in momentary levels of fatigue, pain, depressive symptoms, confidence, and happiness after engaging in MVPA, using ecological momentary assessment at 6 months. Inactive adults with arthritis (n=285) will receive a 6-month adaptive physical activity intervention. Participants will be randomized to receive one of 3 doses of MVPA: (1) 45 min/week, (2), 90 min/week, or (3) 150 min/week. MVPA goals will begin lower and gradually increase towards the 45, 90, or 150 min/week goal every 2 weeks. Participants will be encouraged to spread the MVPA out over at least 3 days. To help participants achieve goals, they will be provided with the Arthritis Foundation’s Walk With Ease Guidebook, behavioral lessons, monthly behavioral telephone coaching, and a Fitbit. If a participant achieves less than 80% of his/her goal for a given week, or does not track his/her activity for the week, the participant will be stepped up to receive additional intervention components (e.g., text message/email, biweekly or weekly coaching calls). Objectively-assessed MVPA and arthritis-attributable outcomes will be obtained at the baseline, 6-, and 12-month assessments. Momentary arthritis-attributable outcomes will be obtained through ecological momentary assessment at 6 months. Results from this randomized controlled trial will provide insight on whether adults with arthritis can experience benefits from engaging in less physical activity than what is currently recommended. Additionally, gaining a better understanding of how long and short durations of activity influence momentary symptoms will provide clinical and public health implications for prescribing specific activity goals. Key study findings will be disseminated to academic and practitioner audiences as well as additional avenues informed by our partners.