UpToDate is a web-based, clinical information resource, designed to provide concise, practical answers to clinical questions. The content is updated quarterly. Nearly 3,000 author physicians continually review the literature for material that is well supported by data and would be useful in a clinical setting. If a medical finding is deemed important, it is then added to the relevant topic review(s) after approval by an internal peer review and by the authors. The content is comprehensive, concise, and fully referenced.