The authors of the article entitled “Tiotropium for stable chronic obstructive pulmonary disease: a meta-analysis” (Barr RG, Bourbeau J, Camargo CA, et al. Thorax 2006;61:854–62), published in the October issue, have noticed an error in figure 1. Reference 26 in figure 1 should refer to a paper not in the reference list:

. Where reference 26 is cited in the text this correctly refers to the paper listed in the reference list.