1 Retraction to: Clin Drug Investig 2009; 29(7):471–479 https://doi.org/10.2165/00044011-200929070-00005

The Editor-in-Chief has retracted this article because two of the three studies [1, 2] included in the meta-analysis (cited as references 11 and 12) have been retracted due to fabrication of the data, which has rendered the results of this meta-analysis invalid.

All authors agreed to this retraction.