A note on the evaluation of BoNTA trial quality.

In their systematic review, Zhang et al. evaluate randomized controlled trials on the efficacy of Botulinum toxin type A (BoNTA) in helping patients with musculoskeletal disorders. Scoring each trial according to the Jadad scale they note that the studies range from 1 to 5 with an average of 4.1, which they interpret as a testimony of the high quality of the studies included. Unfortunately, we cannot share the author's enthusiasm, as a perfect Jadad score of 5 is no guarantee that a study is of good quality.