Objectives: The aim of the study was to identify prognostic factors for the persistence of chronic abdominal pain (CAP) in children. Materials and Methods: For this systematic review, MEDLINE, EMBASE, and PsycINFO were searched up to June 2008 for prospective follow-up studies of pediatric CAP as defined by the criteria of Apley, von Baeyer, or the Rome Committee. The outcome measure of interest was persistence of CAP. Persistent CAP was considered only when the abdominal pain of children with CAP persisted during follow-up at the same level of frequency and severity. For each study the risk for bias was assessed. The evidence for prognostic factors was summarized according to a best-evidence synthesis. Results: Eight studies, which examine...