Abstract
Background Telephone-based support offers a promising option to provide widely accessible and cost-effective weight loss care to the people with knee osteoarthritis who are overweight. While telephone-based interventions targeting weight loss are used routinely in the general populations, the cost-effectiveness of referring patients with knee osteoarthritis to these is unknown. The aim of this study was to assess the cost-effectiveness of referral to a telephone-based weight management and healthy lifestyle service for patients with knee osteoarthritis, who are overweight or obese, compared to usual care.
Methods We randomised 120 patients with knee osteoarthritis to an intervention or usual care control group in a 1:1 ratio. Participants in the intervention group received a referral to an existing non-disease specific 6-month telephone-based weight management and healthy lifestyle service. The primary outcome of the study was quality-adjusted life years (QALYs). Secondary outcomes included pain intensity, disability, weight, and body mass index (BMI). Costs included intervention costs, healthcare utilisation costs (healthcare services and medication use) and absenteeism costs due to knee pain. The primary cost-effectiveness analysis was performed from the societal perspective.
Results Mean cost differences between groups (intervention minus control) were, $454 (95%CI: −2735 to 4206) for healthcare costs, $-36, (95%CI: −73 to 2) for medication costs, and $-13 (95%CI: −225 to 235) for absenteeism costs. The total mean difference in societal costs was $1022 (95%CI: −2201 to 4771). For all outcomes, the probability of the intervention being cost-effective compared with usual care was less than 0.33 at all willingness-to-pay values.
Conclusion From a societal perspective, telephone-based weight loss support, provided using an existing non-disease specific 6-month weight management and healthy lifestyle service was not cost-effective in comparison with usual care for overweight and obese patients with knee osteoarthritis for QALYs, pain intensity, disability, weight, and BMI.