A pilot randomized trial of a novel intervention to promote physical activity in people with knee osteoarthritis : protocol and baseline analysis from the TRACK-OA study

Objectives: (1) Develop a protocol for a pilot randomized controlled trial (RCT) of a novel physical activity (PA) counseling intervention to increase bouted moderate-to-vigorous physical activity (MVPA) time (bout ≥ 10 minutes at ≥ 3 Metabolic Equivalents [METs]) and decrease bouted sedentary time (bout > 20 minutes at ≤ 1.5 METs) for people with knee osteoarthritis (OA), and (2) conduct a secondary baseline analysis to assess the relationships between a measure of patient engagement and bouted MVPA time, as well as bouted sedentary time. Methods: A protocol for a pilot RCT was developed and published. Feasibility objectives related to study processes, resources, management, and effectiveness were set. Inclusion criteria were a diagnosis of knee OA or having experienced four weeks of knee symptoms during the last year, no inflammatory arthritis, and no contra-indications to being active. Patient engagement was measured with the Partners in Health Scale (PIH). MVPA and sedentary time were measured with the BodyMedia SenseWear Mini (SW). Knee OA status was assessed with the Knee injury and OA Outcome Score. Bivariate and stepwise regression analyses were performed to estimate the relationship between PIH and bouted MVPA/sedentary time. Results: Participants (female = 28, male = 6), were aged [mean (standard deviation [SD])] 55.5 (8.6) years, with a BMI of 27.2 (4.7) kg/m². The sample indicated a PIH of 24.4 (16.4), 53.9 (62.4) minutes of daily bouted MVPA, and 508.9 (178.9) minutes of bouted sedentary time. Regression analysis [b (standard error [SE]) where b indicates estimated regression coefficient] found log-transformed bouted MVPA was not associated with PIH, but was negatively associated with age, b = -0.042 (0.018; p < 0.01) and BMI, b = -0.15 (0.031; p < 0.001). Bouted sedentary time was not associated with PIH, but was positively associated with BMI, b = 27.47 (4.29; p < 0.001) and female sex, b = 156.01 (51.93; p < 0.001). Conclusion: Patient engagement may not be associated with objectively-measured physical activity among people living with knee OA, methodological factors and a small sample size may have contributed to the findings. Further work is needed to clarify these relationships.Medicine, Faculty ofGraduat