The review was initially funded by the UK NHS R&D Programme, project no 96/37/01. The views expressed in the review do not necessarily reflect those of the programme. Updates to the review have been supported by an NHS R&D Primary Care Career Scientist Award held by Professor Delaney.

Dr. Cathy Bennett, formerly Co‐ordinator of the Cochrane Upper Gastrointestinal and Pancreatic Group, was of invaluable help throughout the review and we are most grateful to her for her advice and support. Janet Lilleyman, currently Co‐ordinator of the Cochrane Upper Gastrointestinal and Pancreatic Group has considerably improved the readability of the original version of this review.

The original published review in 2000 was conducted by the Prof Delaney, Prof Moayyedi and Prof Forman, assisted by Dr Michael Innes, Dr Sue Wilson and Ms Rachel Oakes. Mr Jon Deeks provided statistical advice.

Dr M Cooner assisted with the update in 2002.

Dr Alex Ford and Dr M Qume assisted with the IPD analysis and the 2005 update.

We would like to thank all authors, experts and pharmaceutical companies that we contacted and who took the time to reply.

We are particularly indebted to those authors who provided extra data and information from their studies, in particular: Professor Richard Logan, Nottingham, Professor R. H. Jones, Wolfson Professor, GKT, London, Dr. M. E. Numans and Dr. NT Lewin‐van den Broek both from the Department of Primary Care and General Practice University of Utrecht, Netherlands, Dr Richard Stevens, GP Oxford, Dr Garth Baxter, Wyeth, Professor K E McColl, Glasgow, Dr N Chiba, Guelph, Canada, Dr N Arents, The Netherlands, Dr P Myres, Wales.
Finally we are grateful to J Rayworth, Librarian at Leeds University Medical Library for her invaluable help with retrieving citations, and to Iris Gordon, Cochrane UGPD Group for the updated searches.