*Web site addresses up to date as of Dec. 28, 1999. This list was produced by Tom Oliver of the Canadian Cochrane Centre and Jennifer Briand of HEALNet. A more extensive list, including links to international organizations, can be found at hiru.mcmaster.ca/cochrane/centres/canadian/evidence-based.htm.
The Web site of the Institute for Health and Outcomes Research was inactive at the time this article was prepared for publication, but information on reactivation is to be posted at the site listed when it becomes available.