Methods
TOPKAT compared the clinical and cost effectiveness of total or partial knee replacements for medial compartment osteoarthritis. An additional assessment at 1 year post surgery of the primary outcome measure, Oxford Knee Score (OKS) was administered to patients who had a waiting time following randomisation of greater than 12 weeks as well as baseline and post-randomisation follow-up. Mean difference (MD) between treatments (95% confidence interval (CI)) was calculated using 1 year post-surgery and post-randomisation data.