An editorial error occurred in the second letter of this cluster by Allan Hackshaw et al (11 November, pp 1221-2). The word “not” was omitted from the third paragraph, which should have read: “There is further evidence against material publication bias in that 32 of the 39 studies reported non-significant results and in 16 (41%) the authors had either concluded that there was no effect13 or that the evidence was inconclusive3, suggesting that the passive smoking literature is not one with a strong tendency for positive results to be published while negative results remain unpublished.”