Telephone-based weight loss support for patients with knee osteoarthritis: a pragmatic randomised controlled trial

Objective: To determine the effectiveness of telephone-based weight loss support in reducing the intensity of knee pain in patients with knee osteoarthritis, who are overweight or obese, compared to usual care. Design: We conducted a parallel randomised controlled trial (RCT), embedded within a cohort multiple RCT of patients on a waiting list for outpatient orthopaedic consultation at a tertiary referral hospital in NSW, Australia. Patients with knee osteoarthritis, classified as overweight or obese [body mass index (BMI) between >= 27 kg/m(2) and <40 kg/m(2)] were randomly allocated to receive referral to an existing non-disease specific government funded 6-month telephone-based weight management and healthy lifestyle service or usual care. The primary outcome was knee pain intensity measured using an 11-point numerical rating scale (NRS) over 6-month follow-up. A number of secondary outcomes, including self-reported weight were measured. Data analysis was by intention-to-treat according to a pre-published analysis plan. Results: Between May 19 and June 30 2015, 120 patients were randomly assigned to the intervention (59 analysed, one post-randomisation exclusion) or usual care (60 analysed). We found no statistically significant between group differences in pain intensity [area under the curve (AUC), mean difference 5.4, 95% CI: -13.7 to 24.5, P = 0.58] or weight change at 6 months (self-reported; mean difference -.4, 95% CI: -2.6 to 1.8, P = 0.74). Conclusions: Among patients with knee osteoarthritis who are overweight, telephone-based weight loss support, provided using an existing 6-month weight management and healthy lifestyle service did not reduce knee pain intensity or weight, compared with usual care. (C) 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.