Systematic Reviews. Systematic, critical assessments of literature and data sources pertaining to clinical topics, emphasizing factors such as cause, diagnosis, prognosis, therapy, or prevention. All articles and data sources reviewed should include information about the specific type of study or analysis, population, intervention, exposure, and tests or outcomes. All articles or data sources should be selected systematically for inclusion in the review and critically evaluated, and the selection process should be described in the article. Typical length: 2000 to 4000 words (not including tables, figures, and references). See recent examples of systematic reviews in Archives.3-Â 4