title: Evaluation of published clinical studies for reproducibility, comparability and adherence to evidence-based methods.
abstract: OBJECTIVE
  To evaluate the "Materials and Methods" of long-term clinical studies in relation to documentation, reproducibility and comparability with and without employing the systematic methods of evidence-based medicine.
  
  
  METHODS
  The "Materials and Methods" sections in 45 clinical long-term published studies of direct posterior resin-based composite restorations were evaluated for their use of systematic methods of evidence-based medicine. The search was limited to the years 1988-1997, using the key words "clinical study/evaluation/results/report, long-term, in vivo, posterior, Class I/II, composite, restoration". Special attention was directed to comparisons of the underlying documentation, descriptions of the operative techniques used, and their reproducibility. In addition, an evidence-based search was carried out using the Internet PubMed interface for MEDLINE, using identical synonyms, to identify studies with high levels of quality of evidence. Documentation, reproducibility, and comparability of "Materials and Methods" were also evaluated.
  
  
  RESULTS
  Results revealed how difficult it is to interpret results based on tenuous premises, subjective standards, and inadequate study designs. Only one article could be identified when the search was limited to "humans" and "randomized clinical trials". None of the articles, even when fulfilling the highest quality of evidence, showed sufficient or satisfactory quality of reproducibility in their descriptions in Materials and Methods.
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cariology, Dental Institute, Zürich University, Switzerland. schmidli@zzmk.unizh.ch
authors.forename: Schmidlin
authors.initials: S
authors.lastname: Patrick
authors.forename: Esther
authors.initials: E
authors.lastname: Hofer
authors.forename: Felix
authors.initials: F
authors.lastname: Lutz
mesh_terms: D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D003188:Composite Resins; D003793:Dental Restoration, Permanent; D004282:Documentation; D019317:Evidence-Based Medicine; D006801:Humans; D020407:Internet; D016239:MEDLINE; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design
chemical_list: D003188:Composite Resins