It has come to our attention that one of the 95% CIs included in our analyses was incorrect. For the Nine Hospital Study the RR (95% CI) for chewing tobacco, given in Table 3 as 2.82 (0.95-9.39), should in fact be 2.82 (0.85-9.39). The error has no substantive effect on the conclusions drawn in the paper, and does not affect the wording of the text. It does, however, slightly affect some of the relative risks and 95% confidence intervals in the eta-analyses reported in Tables 4 and 5. With the corrected values of the meta-analyses, the fifth paragraph of the abstract should read: “Giving preference to estimates for never smokers, if available, and overall population estimates otherwise, the estimate was 1.13 (0.67-1.92), again based on heterogeneous estimates. Estimates varied (p = 0.012) between cohort studies (1.75, 1.20-2.54) and case-control studies (0.83, 0.36-1.93). The value for cohort studies derived mainly from one study, which reported an increase for never smokers (2.0, 1.2-3.3), but not overall (0.9, 0.7-1.2). This study also contributed to increases seen for snuff use and for European studies, significant only in fixed-effect analyses.” Other sections where the meta-analysis results are similarly affected. We apologise for this error and are grateful to the reader who brought it to our attention. Please address any queries concerning the correction to. Peter Lee, who would be happy to supply full details of the revised meta-analyses. Zheng Sponsiello-Wang, Rolf Weitkunat and Peter N Lee 11th June 2009
Correction of an error
23 June 2009
It has come to our attention that one of the 95% CIs included in our analyses was incorrect. For the Nine Hospital Study the RR (95% CI) for chewing tobacco, given in Table 3 as 2.82 (0.95-9.39), should in fact be 2.82 (0.85-9.39). The error has no substantive effect on the conclusions drawn in the paper, and does not affect the wording of the text. It does, however, slightly affect some of the relative risks and 95% confidence intervals in the eta-analyses reported in Tables 4 and 5.
With the corrected values of the meta-analyses, the fifth paragraph of the abstract should read:
“Giving preference to estimates for never smokers, if available, and overall population estimates otherwise, the estimate was 1.13 (0.67-1.92), again based on heterogeneous estimates. Estimates varied (p = 0.012) between cohort studies (1.75, 1.20-2.54) and case-control studies (0.83, 0.36-1.93). The value for cohort studies derived mainly from one study, which reported an increase for never smokers (2.0, 1.2-3.3), but not overall (0.9, 0.7-1.2). This study also contributed to increases seen for snuff use and for European studies, significant only in fixed-effect analyses.”
Other sections where the meta-analysis results are similarly affected.
We apologise for this error and are grateful to the reader who brought it to our attention. Please address any queries concerning the correction to. Peter Lee, who would be happy to supply full details of the revised meta-analyses.
Zheng Sponsiello-Wang, Rolf Weitkunat and Peter N Lee
11th June 2009
Competing interests
None other than stated in the original paper