FIGURE A-1 Categorization of studies on testosterone therapy.

domized controlled trials or clinical trials. In sorting through the results, it was useful to categorize the studies as shown in Figure A-1. The clinical trials of interest are those that are placebo-controlled and in which the participants were middle-aged or older men. As discussed in Chapter 2, the committee focused its review on the randomized placebo-controlled trials conducted in older men. A review of this literature was provided through a contract with Research Triangle Institute (RTI). RTI staff performed a Medline search using the key words testosterone and androgens. The search was limited to English language articles published between 1990 and 2003, and targeted to include placebo-controlled trials in older men. This search, which was last updated on May 1, 2003, yielded 285 abstracts. Additional references were identified by reviewing the reference lists of major review articles and relevant books and by references supplied by IOM staff. The most recently published systematic review by Gruenewald and Matsumoto (2003) was particularly helpful. In total, RTI