The EB on-call process		How we create the EB On-call database Clinical topics are selected if they commonly present in the emergency department, require early effective management to prevent serious complications, or often confuse or perplex doctors on-call. The literature is searched by two researchers specifically targeting Best Evidence, the Cochrane Library, Medline and other databases looking for the best quality material available. Search details are listed at the end of each CAT. High-quality EBM methods are maintained by using open and explicit selection and appraisal criteria. Articles are selected and appraised by a researcher or clinician with EBM experience. Each article is turned into a one-page summary called a critically-appraised topic (or CAT) and added to a central electronic database. The appraisal process is repeated by another contributor, then the CAT is peer-reviewed by a clinical expert for clinical validity. Each CAT graded for quality by the review editor. CATs are used to create the clinical guides. Each guide combines practical advice with the evidence that supports it. Each guide is peer-reviewed by a clinician. All CATs and guides have expiry dates – once reached, a search of the literature is repeated automatically. Researchers scan secondary review journals and EBM databases in the intervening period, so that the information is constantly updated.