title: GI Epidemiology: databases for epidemiological studies.
abstract: BACKGROUND
  Large databases are being increasingly used for examining the epidemiology and outcomes of digestive and liver disorders. The complexity and rigor of the methods used to conduct these studies are often underestimated.
  
  
  OBJECTIVE
  For the most commonly used databases, we provide a brief description of the contents, highlight strengths and weakness, and provide links for more detailed information. We also present a systematic approach to utilizing large databases for addressing research questions, highlighting commonly encountered study design issues, as well as strategies for resolving these issues.
  
  
  CONCLUSIONS
  1. Research using large databases requires the same essential skills needed to conduct research studies using other data sources. These include a rigorous study design, expertise in analytic methods, and relevant research questions. 2. The completeness and accuracy of information contained in the database must be assessed. Methods for improving the quality and completeness of this information should be considered. 3. Despite similarities among large databases, gaining insight and experience into the structure and content of each database is essential. Key points *Large databases can be a powerful source of information to examine the clinical epidemiology and outcomes of digestive and liver disorders. * Research using large databases requires the same essential skills needed to conduct research studies using other data sources. These include a rigorous study design, expertise in analytic methods, and relevant research questions. * The completeness and accuracy of information contained in the database must be assessed. Methods for improving the quality and completeness of this information should be considered. * Despite similarities among large databases, gaining insight and experience into the structure and content of each database is essential. * Examples of commonly used large databases are presented with a synopsis of information contained in the database, as well as strengths and limitations of using the database for research.
authors.forename: J A
authors.initials: JA
authors.lastname: Davila
authors.forename: H B
authors.initials: HB
authors.lastname: El-Serag
mesh_terms: D019992:Databases as Topic; D004066:Digestive System Diseases / Q000453:epidemiology*; D016021:Epidemiologic Studies; D006801:Humans