http://bmj.com/cgi/content/full/328/7430/30 Updated information and services can be found at: These include: Data supplement http://bmj.com/cgi/content/full/328/7430/30/DC1 "Additional references" References http://bmj.com/cgi/content/full/328/7430/30#otherarticles 13 online articles that cite this article can be accessed at: http://bmj.com/cgi/content/full/328/7430/30#BIBL This article cites 2...
