On behalf of the Agency for Healthcare Research and Quality, the Vanderbilt Evidence-based Practice Center systematically reviewed evidence on treatment of OAB, urge UI, and related symptoms. These investigators focused on prevalence and incidence, treatment outcomes, comparisons of treatments, modifiers of outcomes, and costs. They included studies published in English from January 1966 to October 2008; and excluded studies with fewer than 50 subjects, fewer than 75 % women, or lack of relevance to OAB. Of 232 included publications, 20 were good quality, 145 were fair, and 67 poor. These researchers calculated weighted averages of outcome effects and conducted a mixed-effects meta-analysis to examine outcomes of pharmacotherapies across studies.