title: Have we progressed in the surgical literature? Thirty-year trends in clinical studies in 3 surgical journals.
abstract: BACKGROUND
  We practice in an era of evidence-based medicine. In 1993, Solomon and McLeod published an article examining study designs in 3 surgical journals from 1980 and 1990.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate subsequent 30-year trends in the quality of selected literature.
  
  
  METHODS
  All of the articles from Diseases of the Colon & Rectum, Surgery, and the British Journal of Surgery during 2000 and 2010 were classified by study design. Nonclinical studies were substratified by animal/laboratory, surgical technique, editorial/review, or miscellaneous articles. Clinical articles were categorized as case or comparative studies, further categorized by study design, and rated on a 10-point scale to determine strength. We compared interobserver reliability using a random sample.
  
  
  METHODS
  This study was conducted at 3 North American medical centers.
  
  
  METHODS
  Patients described in the scope of the literature were included in this study.
  
  
  METHODS
  Frequency, type, and strength of study design were measured.
  
  
  RESULTS
  We evaluated 1911 articles (967 clinical; 17% comparative). There was a significant increase in multicenter clinical studies (from 12% to 27%; p < 0.0001) and mean study population (from 326 to 6775; p < 0.05). Studies using administrative data increased from 14% to 43% (p < 0.0001). Case reports decreased from 16% to 7% of all clinical studies (p < 0.001), whereas the percentage of comparative studies increased from 14% to 21% (p = 0.001). The percentage of randomized controlled trials did not increase significantly (8.5% in 2000; 10.0% in 2010; p = 0.44). The mean 10-point score for comparative studies was 6.7 for both years (p = 0.50). There was good interobserver agreement in the classification of studies (κ = 0.70) and moderate agreement in scoring comparative studies (κ = 0.47).
  
  
  CONCLUSIONS
  This descriptive study cannot fully account for the reasons behind the identified differences.
  
  
  CONCLUSIONS
  Comparative and multicenter studies, mean study population, and the use of administrative data increased from 2000 to 2010. This suggests that increased use of administrative databases has allowed larger populations of patients from more institutions to be studied and may be more generalizable. Researchers should strive toward improving the level of evidence (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A167).
authors.affiliation: 1 Department of Surgery, Madigan Army Medical Center, Fort Lewis, Washington 2 Department of Surgery, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada 3 Department of Surgery, UMass Memorial Medical Center, University of Massachusetts Medical School, Worcester, Massachusetts.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Shawhan
authors.forename: Quinton M
authors.initials: QM
authors.lastname: Hatch
authors.forename: Jason R
authors.initials: JR
authors.lastname: Bingham
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Nelson
authors.forename: Emile B
authors.initials: EB
authors.lastname: Fitzpatrick
authors.forename: Robin
authors.initials: R
authors.lastname: McLeod
authors.forename: Eric K
authors.initials: EK
authors.lastname: Johnson
authors.forename: Justin A
authors.initials: JA
authors.lastname: Maykel
authors.forename: Scott R
authors.initials: SR
authors.lastname: Steele
mesh_terms: D015706:Bibliometrics; D035843:Biomedical Research / Q000639:trends*; D002986:Clinical Trials as Topic / Q000639:trends; D019317:Evidence-Based Medicine; D006801:Humans; D015337:Multicenter Studies as Topic / Q000639:trends; D010506:Periodicals as Topic / Q000639:trends*; D011643:Publishing / Q000639:trends*; D015203:Reproducibility of Results; D012107:Research Design; D013514:Surgical Procedures, Operative / Q000639:trends*