Sample size formula for proportional hazards modelling of competing risks

Stat Med. 2004 Nov 15;23(21):3263-74. doi: 10.1002/sim.1915.


To test the effect of a therapeutic or prognostic factor on the occurrence of a particular cause of failure in the presence of other causes, the interest has shifted in some studies from the modelling of the cause-specific hazard to that of the subdistribution hazard. We present approximate sample size formulas for the proportional hazards modelling of competing risk subdistribution, considering either independent or correlated covariates. The validity of these approximate formulas is investigated through numerical simulations. Two illustrations are provided, a randomized clinical trial, and a prospective prognostic study.

MeSH terms

  • Administration, Intravaginal
  • Cohort Studies
  • Computer Simulation
  • Delivery, Obstetric
  • Dinoprostone / administration & dosage
  • Dinoprostone / therapeutic use
  • Double-Blind Method
  • Female
  • Graft vs Host Disease / etiology
  • Humans
  • Leukemia / therapy
  • Misoprostol / administration & dosage
  • Misoprostol / therapeutic use
  • Oxytocics / therapeutic use
  • Pregnancy
  • Proportional Hazards Models*
  • Randomized Controlled Trials as Topic / methods*
  • Risk Factors
  • Sample Size*
  • Stem Cell Transplantation


  • Oxytocics
  • Misoprostol
  • Dinoprostone