Survival rates from interval cancer in NHS breast screening programme.

We thank hospital staff at all four centres for their help with data collection, and Dr David Owens and an anonymous referee for their comments on earlier drafts of this paper. Contributors: NK helped with the study design, collected and analysed all data, and contributed to writing the initial draft of the paper. AH helped to design the study and contributed to writing the initial draft of the paper. FC, EF, TF, and EG contributed to final aspects of study design, helped collect data, and commented on drafts of the paper. NK and AH are guarantors for the study. Funding: This study was funded by the Medical Research Council, grant number G9533540, to AH, FC, Professor K Hawton, and Professor M Williams. At the time of this study NK was supported by the Medical Research Council and Leeds Community Mental Health Trust. Conflict of interest: None.