Open Access. The Published version of this work has been reproduced here in accordance with the Publisher’s self archiving and copyright policies.
This article may be downloaded for personal use only. Any other use requires prior permission of Cambridge University Press. This work was published in International Journal of Technology Assessment in Health Care, 20, (2), 2004 p.128-144 published by Cambridge University Press and can be found at Cambridge Journals online http://dx.doi.org/10.1017/S0266462304000911
Copyright (2004) Cambridge University Press
International Journal of Technology Assessment in Health Care, 20(2): 128-144