First Author:   Arne Risa Hole National Primary Care Research and Development Centre, Centre for Health Economics, University of York ah522@york.ac.uk   Centre for Health Economics, Alcuin 'A'' Block, University of York York, YO10 5DD, UK   +44 1904 321404(Phone) +44 1904 321404(Fax) http://www-users.york.ac.uk/~ah522/home.htm