The authors have retracted this article that reports their presentation at a conference because the data have been published previously in their Letter to The Lancet [1]. The authors wish to correct the literature by removing this unintentional duplication of data. M. Tschöp, C.J. Strasburger, M. Töpfer, H. Hautmann, R. Riepl, R. Fischer, G. Hartmann, K. Morrison, and P. Bärtsch agree with this retraction. W. Hildebrandt has not responded to correspondence from the Publisher about this retraction. The Publisher has not been able to obtain current email addresses for M. Appenzeller and J. Biollaz.