title: P-Hacking in Orthopaedic Literature: A Twist to the Tail.
abstract: BACKGROUND
  "P-hacking" occurs when researchers preferentially select data or statistical analyses until nonsignificant results become significant. We wanted to evaluate if the phenomenon of p-hacking was evident in orthopaedic literature.
  
  
  METHODS
  We text-mined through all articles published in three top orthopaedic journals in 2015. For anonymity, we cipher-coded the three journals. We included all studies that reported a single p value to answer their main hypothesis. These p values were then charted and frequency graphs were generated to illustrate any evidence of p-hacking. Binomial tests were employed to look for evidence of evidential value and significance of p-hacking.
  
  
  RESULTS
  Frequency plots for all three journals revealed evidence of p-hacking. Binomial tests for all three journals were significant for evidence of evidential value (p < 0.0001 for all). However, the binomial test for p-hacking was significant only for one journal (p = 0.0092).
  
  
  CONCLUSIONS
  P-hacking is an evolving phenomenon that threatens to jeopardize the evidence-based practice of medicine. Although our results show that there is good evidential value for orthopaedic literature published in our top journals, there is some evidence of p-hacking of which authors and readers should be wary.
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Singapore hamidrazak@gmail.com.
authors.forename: Hamid Rahmatullah
authors.initials: HR
authors.lastname: Bin Abd Razak
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Jin-Guang Ernest
authors.initials: JE
authors.lastname: Ang
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Hersh
authors.initials: H
authors.lastname: Attal
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Singapore.
authors.forename: Tet-Sen
authors.initials: TS
authors.lastname: Howe
authors.affiliation: Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore.
authors.forename: John Carson
authors.initials: JC
authors.lastname: Allen
mesh_terms: D015706:Bibliometrics; D006801:Humans; D009985:Orthopedics / Q000941:ethics*; D011643:Publishing / Q000941:ethics*; D013223:Statistics as Topic / Q000941:ethics*