title: Low immediate scientific yield of the PhD among medical doctors.
abstract: BACKGROUND
  We studied the scientific yield of the medical PhD program at all Danish Universities.
  
  
  METHODS
  We undertook a retrospective observational study. Three PhD schools in Denmark were included in order to evaluate the postdoctoral research production over more than 18 years through individual publications accessed by PubMed.
  
  
  RESULTS
  A total of 2686 PhD-graduates (1995-2013) with a medical background were included according to registries from all PhD schools in Denmark. They had a median age of 35 years (interquartile range (IQR), 32-38) and 53 % were women at the time of graduation. Scientific activity over time was assessed independently of author-rank and inactivity was measured relative to the date of graduation. Factors associated with inactivity were identified using multivariable logistic regression. 88.6 % of the PhD theses were conducted in internal medicine vs. 11.4 % in surgery. During follow-up (median 6.9 years, IQR 3.0-11.7), PubMed data searches identified that 87 (3.4 %) of the PhD graduates had no publication after they graduated from the PhD program, 40 % had 5 or less, and 90 % had 30 or less. The median number of publications per year after PhD graduation was 1.12 (IQR 0.61-1.99) papers per year. About 2/3 of the graduates became inactive after 1 year and approximately 21 % of the graduates remained active during the whole follow-up. Female gender was associated with inactivity: adjusted odds ratio 1.59 (95 % confidence interval 1.24-2.05).
  
  
  CONCLUSIONS
  The scientific production of Danish medic PhD-graduates was mainly produced around the time of PhD-graduation. After obtaining the PhD-degree the scientific production declines suggesting that scientific advance fails and resources are not harnessed.
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Emil L
authors.initials: EL
authors.lastname: Fosbøl
authors.affiliation: The Technical University of Denmark, Lyngby, Denmark.
authors.forename: Philip L
authors.initials: PL
authors.lastname: Fosbøl
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Sofie
authors.initials: S
authors.lastname: Rerup
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Lauge
authors.initials: L
authors.lastname: Østergaard
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Mohammed H
authors.initials: MH
authors.lastname: Ahmed
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Jawad
authors.initials: J
authors.lastname: Butt
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Julie
authors.initials: J
authors.lastname: Davidsen
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Nirusiya
authors.initials: N
authors.lastname: Shanmuganathan
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark.
authors.forename: Simon
authors.initials: S
authors.lastname: Juul
authors.affiliation: Department of Cardiology B, University Hospital of Copenhagen, Rigshospitalet Blejdamsvej 9, 2100, København Ø, Denmark. christianlewinter@gmail.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Lewinter
mesh_terms: D000328:Adult; D035843:Biomedical Research / Q000706:statistics & numerical data*; D003718:Denmark; D004500:Education, Graduate / Q000592:standards / Q000706:statistics & numerical data*; D004526:Efficiency; D005260:Female; D006801:Humans; D007396:Internship and Residency; D008297:Male; D017712:Peer Review, Research; D010820:Physicians / Q000706:statistics & numerical data*; D012042:Registries; D012189:Retrospective Studies; D013337:Students, Medical / Q000706:statistics & numerical data*
keywords: Danish PhD schools; Medical degree; Medicine; Observational study; Peer-reviewed publications; PhD; Surgery