title: Increasing complexity of clinical research in gastroenterology: implications for the training of clinician-scientists.
abstract: OBJECTIVE
  Significant advances have been made in clinical and epidemiologic research methods over the past 30 years. We sought to demonstrate the impact of these advances on published gastroenterology research from 1980 to 2010.
  
  
  METHODS
  Twenty original clinical articles were randomly selected from each of three journals from 1980, 1990, 2000, and 2010. Each article was assessed for topic, whether the outcome was clinical or physiologic, study design, sample size, number of authors and centers collaborating, reporting of various statistical methods, and external funding.
  
  
  RESULTS
  From 1980 to 2010, there was a significant increase in analytic studies, clinical outcomes, number of authors per article, multicenter collaboration, sample size, and external funding. There was increased reporting of P values, confidence intervals, and power calculations, and increased use of large multicenter databases, multivariate analyses, and bioinformatics.
  
  
  CONCLUSIONS
  The complexity of clinical gastroenterology and hepatology research has increased dramatically, highlighting the need for advanced training of clinical investigators.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA. frankis@mail.med.upenn.edu
authors.forename: Frank I
authors.initials: FI
authors.lastname: Scott
authors.forename: Ryan A
authors.initials: RA
authors.lastname: McConnell
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Lewis
authors.forename: James D
authors.initials: JD
authors.lastname: Lewis
mesh_terms: D035843:Biomedical Research / Q000193:education* / Q000639:trends*; D004813:Epidemiology / Q000193:education; D005762:Gastroenterology / Q000193:education* / Q000639:trends*; D006801:Humans; D011361:Professional Competence; D012107:Research Design / Q000639:trends*; D012108:Research Personnel / Q000193:education* / Q000600:supply & distribution; D012109:Research Support as Topic / Q000639:trends