title: The Completeness of Reporting (CORE) index identifies important deficiencies in observational study conference abstracts.
abstract: OBJECTIVE
  The aim was to develop, test, and apply an index to assess the completeness of reporting in a cohort of observational studies of conference abstracts.
  
  
  METHODS
  Using rigorous methods, we reduced 245 items generated by literature review to 48 candidate items. In a random sample of 30 conference abstracts of rituximab for nonHodgkin lymphoma, we developed an item impact score using a survey of abstract stakeholders combined with the prevalence of each of the 48 items. We retained 14 independent items representing completeness of reporting, the CORE-14. Two raters determined the reliability of the instrument. We then applied the CORE-14 in another 78 studies to determine the prevalence of each feature.
  
  
  RESULTS
  Our survey response rate was 83.9% (47/56). Interrater reliability (95% CI) of the CORE-14 instrument was 0.56 (0.25, 0.77), which improved by averaging across scores provided by two raters (0.72 [0.49, 0.86]). Applying the CORE-14 in an additional set of 78 abstracts, six items occurred > or =85% and four items occurred < or =40% of the time.
  
  
  CONCLUSIONS
  Opportunities to improve conference abstract reporting exist. This scale could guide future conference abstract submissions and aid individuals considering conference abstract data to inform clinical practice, systematic reviews, guidelines, or policy.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Kho
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON; Program for Educational Research and Development, McMaster University, Hamilton, ON.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Eva
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON; Department of Medicine, McMaster University, Hamilton, ON.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Cook
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON; Program in Evidence-Based Care, Cancer Care Ontario, McMaster University, Hamilton, ON. Electronic address: mbrouwer@mcmaster.ca.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Brouwers
mesh_terms: D000043:Abstracting and Indexing / Q000592:standards*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015706:Bibliometrics; D003226:Congresses as Topic; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy; D011643:Publishing / Q000592:standards*; D012107:Research Design; D000069283:Rituximab
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab