annually to subscribers on disk, on CD-ROM, and via the Internet. One of the databases, The Cochrane Database of Systematic Reviews, contains Cochrane reviews, and another, The Cochrane Controlled Trials Register, is a bibliographic database of controlled trials. The Database of Abstracts of Reviews of Effectiveness includes structured abstracts of systematic reviews that have been critically appraised by the National Health Services Centre for Reviews and Dissemination in York, England; the American College of Physicians’ Journal Club; and the journal Evidence-Based Medicine. The library also includes a registry of bibliographic information on nearly 160,000 controlled trials that provide high-quality evidence on health care outcomes.
The Agency for Healthcare Research and Quality’s 12 Evidence-Based Practice Centers conduct systematic, comprehensive analyses and syntheses of the scientific literature on clinical conditions/problems that are common, account for a sizable proportion of resources, and are significant for the Medicare or Medicaid populations (Agency for Healthcare Research and Quality, 2000b). The centers include universities (Duke University, The Johns Hopkins University, McMaster University, Oregon Health Sciences University, the University of California at San Francisco, and Stanford University); research organizations (Meta-Works, the Research Triangle Institute, and the RAND Corporation); and health care organizations and associations (New England Medical Center, and Blue Cross and Blue Shield Association). Since December 1998, evidence reports have been released on the following topics: sleep apnea, traumatic brain injury, alcohol dependence, cervical cytology, urinary tract infection, depression, dysphagia, sinusitis, testosterone suppression, attention deficit/hyperactivity disorder, and atrial fibrillation (Eisenberg, 2000a).
In response to the rapid increase in the volume of and interest in systematic reviews generated by the Cochrane Collaboration, the Evidence-Based Practice Centers, and many other smaller-scale efforts, numerous journals specializing in evidence-based publications have emerged. The first journal devoted exclusively to systematic reviews and meta-analyses was the ACP Journal Club, first published in 1991. There are now a number of evidence-based journals, including Evidence-Based Medicine, Journal of Evidence-Based Health Care, Evidence-Based Cardiovascular Medicine, Evidence-Based Mental Health, and Evidence-Based Nursing, as well as numerous “best-evidence” departments in other journals (Sackett et al., 2000).
One of the most recent evidence-based resources is Clinical Evidence, an “evidence formulary” resulting from a collaborative effort of the British Medical Journal and the American College of Physicians (Godlee et al., 1999). Clinical Evidence is noteworthy because of its focus and organization around common conditions. First published in June 1999, it includes summaries on the prevention and treatment of about 70 such conditions. The summaries are based on systematic reviews and, when these are lacking, individual randomized controlled trials.