A newer list of sites is here: http://www.ohdsi.org/web/wiki/doku.php?id=resources:data_network
Data below are not perfectly updated.
October 2014 survey identified a list of 58 sites. This wiki list represents a dynamic list of sites (updated by members)
Edit the page to add your site (enter size in thousands of patients; eg, 14 000k (=14 million).