Methods
REGRESSIONS
Data measuring participants’ willingness to undergo surgery were collected from a three-arm RCT involving 415 individuals. All 3 groups received access to online information about OA and self-management. Participants in the Exercise group also received 6 consultations with a physiotherapist over 6 months, strengthening exercise and physical activity program, advice about management, and additional educational resources. The Exercise plus weight management group (treatment) received 6 consultations with a dietitian over 6 months, very low-calorie ketogenic diet with meal replacements and resources to support behaviour change (in addition to all elements of the exercise intervention). The Information only (control) group received access to online information about OA and self-management. Participant data received from the PHI was fully anonymised. Approval was not required as this study provides analysis of results from a previously published RCT [At baseline and at 12 months post program completion, the treatment and control groups were surveyed for their willingness for surgery in the near future. Surveys used a 5-point rating scale with terminal descriptors of ‘definitely not willing’ to ‘definitely willing’, with those indicating ‘probably willing’ or ‘definitely willing’ classified as willing to have knee surgery. Participants who indicated they were ‘unsure’ about undergoing knee surgery were grouped separately from participants who indicated a willingness or unwillingness for surgery. Multinomial logistic regressions were conducted to estimate the probability of shifts in a participant’s willingness for surgery status using Stata/SE 17 (StataCorp, TX, USA). Results from the RCT are summarised in 