Guideline Writing Committee (GWC) members review the literature; weigh the quality of evidence for or
against particular tests, treatments, or procedures; and estimate expected health outcomes. In developing
recommendations, the GWC uses evidence-based methodologies that are based on all available data (4-6).
Literature searches focus on randomized controlled trials (RCTs) but also include registries, nonrandomized
comparative and descriptive studies, case series, cohort studies, systematic reviews, and expert opinion. Only
selected references are cited.