Background Psoriasis is a chronic, recurrent skin disease that affects approximately 2–3% of
the world's population, and can significantly impair patients' wellbeing and their physical and
mental functioning. Aim To systematically evaluate the efficacy and safety of ustekinumab
versus placebo for psoriasis. Methods We performed a systematic review of all the relevant
published literature relating to randomized controlled trials (RCTs) of ustekinumab from
1990 to August 2013. Relative ratios (RRs) and 95% confidence intervals (CIs) were …

We read the article by Meng et al. 1 in Clinical and Experimental Dermatology with interest.
We agree that a systematic assessment of the evidence with respect to efficacy and safety of
ustekinumab is valuable to guide physicians in the treatment of patients with psoriasis.
However, we are concerned about one major error in the review by Meng et al. 1 The
authors reported that they included nine randomized controlled trials (RCTs) with a total of
11 381 patients, but the included patients were not derived from 9 independent RCT …