Using SUpported Motivational InTerviewing (SUMIT) to improve physical activity for people with knee osteoarthritis. A pilot, feasibility randomised controlled trial

Introduction: Our primary objective was to determine the feasibility of conducting a fully powered trial to evaluate the clinical effectiveness of using SUpported Motivational InTerviewing (SUMIT) to increase physical activity in people with knee osteoarthritis following a structured education and exercise-therapy program. Our secondary objective was to determine if a worthwhile treatment effect was likely for physical activity, physical endurance, joint-related quality of life (QoL), health-related QoL and pain. Methods: We conducted a pilot, feasibility randomised controlled trial involving people with knee osteoarthritis who had completed the Good Life with osteoArthritis Denmark (GLA:D®) program in Australia. SUMIT involved five motivational interviewing sessions targeting physical activity behaviours, over 10-weeks, supported through access to a multimedia web-based platform. Primary feasibility outcomes included number of eligible participants (aim 6-9 participants being eligible per month), recruitment rate (aim 6 participants recruited per month), adherence to motivational interviewing (attendance for 4/5 sessions (80%)), ActivPAL wear (wearing >16 hours per day); and drop-out rate (<20%). Secondary outcomes included steps per day, daily stepping time, daily cadence >100 steps per minute, daily time with bouts >1-minute, 6-minute walk distance, Knee Osteoarthritis Outcome Score (KOOS), Euroqual 5-dimension 5-long, 30 second chair stand test, walking speed, body mass index (BMI), blood pressure and waist circumference were measured at baseline and 3-months following baseline. Standardised mean differences (effect sizes) for continuous variables were calculated using within group change scores (Review Manager 5.3 The Nordic Cochrane Centre, Copenhagen, Denmark). Results: Thirty-two participants were eligible out of 63 people who expressed interest, were recruited over 7-months (SUMIT, n=17, control, n=15), including 22 females (69%). All feasibility criteria were met or could be achieved by using reasonable amendments in future trials, including 100% adhering to motivational interview session attendance, 100% achieving sufficient ActivPAL wear time, and only two drop-outs (6%). Three outcomes showed small to moderate effect sizes (0.13 to 0.32) in favour of the control group. 11 out of 15 outcomes showed at least moderate effect sizes (>0.30) in favour of the SUMIT group including two outcomes (walking speed and KOOS quality of life) showing a large effect (effect size >0.8). Discussion: Supported motivational interviewing was implemented as intended to target physical activity in people with knee osteoarthritis following a structured education and exercise-therapy program. Modifications would be required to make future trials successful, including methods to identify more eligible participants, and increase recruitment rate (e.g. partnering with high volume clinics and advertising). Secondary findings indicate this intervention may be associated with improved moderate physical activity, but this requires testing in a larger high-quality randomised controlled trial. Impact/Application to the field: • Our study found that motivational interviewing, supported by a web-based multimedia platform, is feasible to target physical activity in people with knee osteoarthritis. • SUMIT may contribute to meaningful improvements in physical activity, knee-related burden, quality of life and function in people with knee osteoarthritis. Declaration: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.