Surrogate and auxiliary endpoints in clinical trials, with potential applications in cancer and AIDS research

Stat Med. 1994 May 15;13(9):955-68. doi: 10.1002/sim.4780130906.


Surrogate endpoints have been defined by Prentice as response variables that can substitute for a 'true' endpoint for the purpose of comparing specific interventions or treatments in a clinical trial. The applicability of this definition, and of related surrogate endpoint criteria, is discussed, with emphasis on cancer and AIDS research settings. Auxiliary endpoints are defined as response variables, or covariates, that can strengthen true endpoint analyses. Specifically, such response variables provide some additional information on true endpoint occurrence times for study subjects having censored values for such times. Auxiliary variables will very frequently be available, and they may be able to be used without making additional strong assumptions. Approaches to the use of auxiliary variables using ideas based on augmented score and augmented likelihood methods are described.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acquired Immunodeficiency Syndrome / mortality
  • Acquired Immunodeficiency Syndrome / prevention & control
  • Acquired Immunodeficiency Syndrome / therapy*
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Chemotherapy, Adjuvant
  • Clinical Trials as Topic / statistics & numerical data*
  • Colonic Neoplasms / drug therapy
  • Colonic Neoplasms / mortality
  • Colonic Neoplasms / pathology
  • Combined Modality Therapy
  • Data Interpretation, Statistical*
  • Fluorouracil / administration & dosage
  • Humans
  • Levamisole / administration & dosage
  • Likelihood Functions
  • Models, Statistical*
  • Neoplasm Staging
  • Neoplasms / mortality
  • Neoplasms / prevention & control
  • Neoplasms / therapy*
  • Randomized Controlled Trials as Topic / statistics & numerical data*
  • Research
  • Survival Analysis
  • Treatment Outcome


  • Levamisole
  • Fluorouracil