The editors of the journal would like to alert readers of this article ^{Reference Bao and Li1} that the reported systematic review is an extension of a previously published systematic review of the same clinical questions by Bischoff et al. ^{Reference Bischoff, Kubilay, Allegranzi, Egger and Petra Gastmeier2} The authors have extended their systematic review to include two studies published after the cutoff point of the previous systematic review. Although cited in their article, the authors did not make the connection with the previous publication transparent to readers of the article.