Interpregnancy interval and risk of preterm birth and neonatal death: retrospective cohort study

Some inconsistencies in confidence intervals appeared in this paper by Gordon C S Smith and colleagues (9 August, pp 313-6). In the third to last sentence of the results section of the abstract, the confidence interval for the adjusted odds ratio of 2.2 (for a short interpregnancy interval being a risk factor for extremely preterm birth) is 1.4 to 3.6 [not 1.3 to 4.6]. In the final sentence of the third paragraph of the Results section of the main article, the confidence intervals for the adjusted odds ratios given should be 1.4 to 3.6 [not 1.3 to 4.6] and 1.3 to 2.0 [1.2 to 2.2]. However, all these data were correct in table 2 in the abridged version and in table 3 in the full version (bmj.com).