Author Contributions: Dr Tonstad had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Williams, Billing, Reeves.
Acquisition of data: Tonstad, Tønnesen, Hajek, Billing, Reeves.
Analysis and interpretation of data: Tonstad, Tønnesen, Hajek, Williams, Billing, Reeves.
Drafting of the manuscript: Tonstad, Tønnesen, Hajek, Billing.
Critical revision of the manuscript for important intellectual content: Tonstad, Tønnesen, Hajek, Williams, Billing, Reeves.
Statistical analysis: Tonstad, Billing.
Obtained funding: Reeves.
Administrative, technical, or material support: Williams.
Study supervision: Reeves.
Financial Disclosures: Dr Tonstad reports receiving honoraria for lecturing and consultancies for Pfizer and other manufacturers of smoking cessation medications; Dr Tønnesen reports receiving honoraria for participation in advisory boards for Pfizer and Sanofi-Aventis and for presentations relating to smoking cessation from Pfizer and GlaxoSmithKline; Dr Hajek reports consulting for manufacturers of smoking cessation medications, including Pfizer; Dr Williams reports stock ownership in Pfizer; and Dr Reeves reports stock ownership in Pfizer. No other disclosures were reported.
Funding/Support: This study was sponsored by Pfizer Inc, which provided funding, study drug and placebo, and monitoring.
Role of the Sponsor: Pfizer Inc was involved in all elements of this study, including but not limited to the study design and monitoring. In addition, the database containing the findings of the 25 individual investigator sites was maintained by Pfizer Inc, and statistical analyses were performed at Pfizer Inc by Mr Billing and Ann Pennington, MS.
Independent Statistical Analysis: Ingar Holme, PhD, professor of biostatistics, University of Oslo, and Ullevål University Hospital, had access to all of the data used in the study and performed an independent analysis. Dr Holme performed analyses of the primary and key secondary end points using logistic regression and cross-tabulations. Results were identical to those obtained by the sponsor. Dr Holme received compensation for this reanalysis from Pfizer Inc.
Varenicline Phase 3 Study Group: Andrew Pipe, MD, University of Ottawa Heart Institute, Ottawa, Ontario; David I. Stewart, MD, Cornwall Medical Centre, Cornwall, Prince Edward Island; Gerald Brosky, MD, MSc, Capital District Health Authority, Centre for Clinical Research, Halifax, Nova Scotia; Ginette Girard, MD, Novabyss Inc, Sherbrooke, Quebec; Gordon Ford, MD, FRCPC, Rockyview General Hospital, Calgary, Alberta; Lew Pliamm, MD, Canadian Phase Onward, Toronto, Ontario; Eva Kralikova, MD, PhD, General University Hospital, Dependence Treatment Department, Prague, Czech Republic; Martin Doessing, MD, Department of Medicine, Frederikssund, Frederiksborg, Denmark; Ronald Dahl, MD, Department of Respiratory Diseases, Aarhus University Hospital, Aarhus, Denmark; Erling Aaserud, MD, Kristianborg Studiescenter DA, Bergen, Hordaland, Norway; Jorn Ossum Gronert, MD, Flattum Legesenter, Honefoss, Buskerud, Norway; Erik Lunell, MD, PhD, Fagerstrom Consulting, Helsingborg, Skane, Sweden; Hans Gilljam, MD, CTP/Samhallsmedicin, Stockholm, Sweden; Johan Herlitz, MD, Division of Cardiology, Sahlgrenska University Hospital, Goteborg, Sweden; Michele D. Reynolds, MD, Radiant Research, Dallas, Tex; Peter D. Londberg, MD, Summit Research Network LLC, Seattle, Wash; Samuel N. Lederman, MD, Radiant Research, West Palm Beach, Fla; John E. Pappas, MD, Central Kentucky Research Associates Inc, Lexington, Ky; Martin Edwards, MD, The Jenner Practice, London, England; Philip Howard, MD, St Helier Hospital, Clinical Trials Unit, London, England; Melvin J. Tonkon, MD, Apex Research Institute, Santa Ana, Calif; David P. Sachs, MD, Division of Pulmonary and Critical Care, Stanford University School of Medicine, Palo Alto, Calif.
Acknowledgment: We acknowledge the contribution of Ingar Holme, PhD, University of Oslo and Ullevål University Hospital, Oslo, Norway, for assistance in the independent analysis of the data, and Kelly Stein Marcus, PhD, from Cardinal Health, Wayne, NJ, for editorial support.