A systematic review including 7 RCTs with a total of 413 subjects was abstracted in DARE. The proportion of patients with nodule volume decrease more than 50% after 1 year was higher in the thyroxine groups (mean 26.5%, range 14.3 to 39.1) than in placebo or no-treatment groups (mean 12.3%, range 0 to 20%) in six of the seven trials, but statistical significance was achieved only in 2 of the trials. With all trials included in the meta-analysis, the risk difference was 16.7% (95% CI 5.8 to 27.6).
Comment: The quality of evidence is downgraded by limitations in review quality (The quality of the included studies was not assessed, and the authors provide no information about how the articles were selected for inclusion).