Clinicians can no longer stay abreast of the rapidly expand- ing knowledge bases related to health. The number of random- ized controlled trials published in MEDLINE (a medical literature database) grew from 5,000 per year in 1978–1985 to 25,000 per year in 1994–2001. Furthermore, contentions that much of the literature may be biased and not applicable to important subsets of target populat…