Statistical Analysis
pain
All randomized patients were included in the analysis using the intention-to-treat principle. For the primary outcome, we used a prespecified linear mixed model in which we constrained the treatment arms to have a common baseline mean,We calculated that with a sample size of 300, assuming 20% loss to follow-up by 26 weeks, Pearson correlation between baseline and 26-week BPI worst pain of 0.5 and 2-sided α of .05 would provide the trial with 80% power to detect a Cohen 