Digitally-delivered exercise for people with knee osteoarthritis

Abstract

Knee osteoarthritis (OA) is one of the most common musculoskeletal conditions. Knee OA imposes a substantial individual and societal burden. This burden is projected to increase due to rising obesity rates and an ageing population and become unsustainable for healthcare systems within the next 15 years. In light of this, it is unacceptable that many people with knee OA are not participating in evidence-based and recommended treatments, such as strengthening exercise and physical activity. This is in part due to issues of access to suitably trained health professionals to prescribe and support recommended exercise as well as the challenges people with knee OA experience adhering to regular exercise. This thesis will explore a novel and scalable method of delivering and supporting evidence-based exercise management to people with knee OA. Specifically, this thesis will develop and rigorously evaluate a self-directed digitally-delivered exercise intervention for people with knee OA.

Study One involved the development of a 24-week automated mobile phone text message intervention to support exercise adherence for people with knee OA. This study used the Behaviour Change Wheel framework which guided the application of evidence and behaviour change theory. The intervention was designed to promote participation in weekly knee strengthening exercise by targeting common exercise facilitators and barriers experienced by people with knee OA.

Study Two reports the methodology of a two-arm parallel-design, assessor- and participant-blinded randomised controlled trial. This study was designed to evaluate a digitally-delivered intervention combining web-based OA and exercise information, physical activity guidance and prescription of a 24-week self-directed knee strengthening regimen (the My Knee Exercise website) supported by the mobile phone intervention designed in Study One, compared to web-based OA and exercise information only (control), in people with knee OA. Primary outcomes were overall knee pain and physical function (WOMAC function), at 24-weeks.

Study Three presents the results of the RCT described in Study Two. In this study 206 people with clinically diagnosed knee OA were recruited from the community across Australia and randomised into one of the two groups. Study findings demonstrate that the self-directed, digitally-delivered exercise intervention resulted in greater improvements in pain and function at 24 weeks, compared to internet-delivered education alone in people with knee OA. These findings may be clinically relevant on a population level.

Study Four qualitatively explored participants’ experience and perceptions of using the self-directed digitally-delivered exercise intervention (n=16). Participants had overall positive experiences with the intervention, valuing its simplicity and comprehensiveness, and most appreciated the regular text message contact as an exercise prompt. However, the messages evoked feelings of guilt for some if weekly exercise was not possible. Additionally, a human presence associated with the intervention appeared important.

Study Five involved a secondary analysis of data from Study Four and explored if certain baseline participant characteristics were potential moderators of the effect of the self-directed digitally-delivered exercise intervention on changes in pain and function at 24 weeks, compared to the control. Except for pain self-efficacy, which moderated change in function but not pain, only weak evidence was found that the selected baseline patient characteristics moderated intervention outcomes.

Collectively, findings of this thesis demonstrate the unsupervised, free-access intervention is an acceptable and efficacious method of providing recommended evidence-based exercise to people with knee OA. Findings of this thesis will inform intervention modifications and can be used to guide the design of future digitally-delivered exercise interventions in people with knee OA or other chronic conditions where exercise is a core treatment.