title: Level of evidence: does it change the rate of publication and time to publication of American Academy of Orthopaedic Surgeons presentations?
abstract: BACKGROUND
  Presentations at the Annual Meetings of the American Academy of Orthopaedic Surgeons (AAOS) are often used to guide clinical practice, although many corresponding manuscripts are not published. The purpose of this study was to determine the relationship between level of evidence, rate of publication, and time to publication of presentations from an AAOS Annual Meeting.
  
  
  METHODS
  A comprehensive literature search for all 756 studies (288 papers and 468 posters) presented at the 2001 AAOS Annual Meeting was performed to determine which of these studies were ultimately published in the peer-reviewed literature. The corresponding AAOS abstracts were each assigned a level of evidence (LOE) with use of a consensus approach and The Journal of Bone and Joint Surgery (JBJS)/AAOS LOE classification system. The rate of publication and mean time to publication for each LOE was then calculated and compared.
  
  
  RESULTS
  The overall publication rate for the 2001 AAOS paper and poster presentations was 49% after five years, and 58% after ten years. At five and ten-year intervals, respectively, 77% and 85% of Level I presentations were published; 69% and 74% of Level II presentations were published; 58% and 66% of Level III presentations were published; and 39% and 51% of Level IV presentations were published. Overall, there was a significant nonrandom difference in publication rates at both five and ten years by LOE (p values of ≤0.001). Level I and II presentations were 2.9 times more likely than Level III and IV presentations to be published after five years (95% confidence interval 1.9 to 4.5), and 2.5 times more likely to be published after ten years (95% confidence interval 1.6 to 4.0). A similar association between LOE and five and ten-year publication rates was observed for both the paper and poster subgroups. The mean time to publication was 0.9 years for Level I studies, 1.4 years for Level II studies, 2.1 years for Level III studies, and 2.7 years for Level IV studies.
  
  
  CONCLUSIONS
  The LOE of AAOS presentations is positively related to rate of publication and inversely related to time to publication. Presentations with higher levels of evidence are published in the peer-reviewed literature at a greater and faster rate than those with lower levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Pramod B
authors.initials: PB
authors.lastname: Voleti
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Donegan
authors.forename: Tae Won B
authors.initials: TW
authors.lastname: Kim
authors.forename: Gwo-Chin
authors.initials: GC
authors.lastname: Lee
mesh_terms: D003226:Congresses as Topic; D019317:Evidence-Based Medicine / Q000145:classification*; D006801:Humans; D009985:Orthopedics; D011643:Publishing / Q000592:standards / Q000706:statistics & numerical data*; D012107:Research Design; D012955:Societies, Medical; D013997:Time Factors; D014481:United States