How much does relapse after one year erode effectiveness of smoking cessation treatments? Long-term follow up of randomised trial of nicotine nasal spray.

We thank the RANX05 Colorectal Cancer Study Group for the collection of the plasma samples. Contributors: HJN and NB had the original idea for and planned the study. HJN was also responsible for collecting the samples and patient data. FM established the database and participated in planning the clinical trial. JG-H developed the enzyme linked immunosorbent assay and analysed all the samples. IJC and HP were responsible for the statistical analyses of the data. The paper was written jointly by NB, KD, JG-H, OT-U, and HJN. HJN and NB are guarantors of the study. Funding: This study received financial support from Glaxo Group Research, United Kingdom; the Kornerup Foundation; the Ingeborg Roikjer Foundation; the University of Copenhagen; the Gerda and Aage Haench Foundation; and the Danish Cancer Society. Conflict of interest: None.