Effects of self-monitoring physical activity with wearable activity trackers on perceived joint function and health-related quality of life in people with hip and knee osteoarthritis: a secondary analysis of a cluster-randomised clinical trial.

Background: Osteoarthritis (OA) often leads to pain and functional limitations, impacting work and daily life. Physical activity (PA) is an important part of the treatment. Wearable activity trackers (WATs) offer a novel approach to promote PA but could also aid in finding a sustainable PA level over time. The aim of this secondary analysis was to examine the effects of self-monitoring PA with a WAT on perceived joint function and health-related quality of life in people with hip and knee OA.

Method: A two-armed cluster-randomized controlled trial (C-RCT) was conducted in southern Sweden including 160 individuals with hip or knee OA. The participants were cluster-randomized to a Supported Osteoarthritis Self-management Program (SOASP) with the addition of self-monitoring PA using a commercial WAT for 12 weeks (n = 86), or only the SOASP (n = 74). The outcomes include perceived joint function measured with HOOS/KOOS and health-related quality of Life (HRQoL) measured with EQ-5D-3L index and EQ VAS. Participants responded to the questionnaires at baseline and at follow-up after 3, 6 and 12 months. Statistical analyses involved linear mixed models, ANCOVA and paired t-test.

Results: Participants with data from baseline and at least one follow-up were included in the analyses (n = 124). The analyses showed no statistically significant differences in changes between the groups in perceived joint function or HRQoL throughout the study period. Both groups improved in pain and symptoms, but the changes were small.

Conclusion: The addition of WAT-use did not have any effect on perceived joint function or HRQoL. The participants' relatively high baseline scores might have influenced the outcomes of this study. We suggest that future WAT-interventions target inactive people with OA and use devices that also captures other activities such as cycling or aquatic exercise.

Trial Registration: ClinicalTrials.gov, NCT03354091. Registered 15/11/2017.