Assessment of futility in clinical trials

Pharm Stat. 2006 Oct-Dec;5(4):273-81. doi: 10.1002/pst.216.


The term 'futility' is used to refer to the inability of a clinical trial to achieve its objectives. In particular, stopping a clinical trial when the interim results suggest that it is unlikely to achieve statistical significance can save resources that could be used on more promising research. There are various approaches that have been proposed to assess futility, including stochastic curtailment, predictive power, predictive probability, and group sequential methods. In this paper, we describe and contrast these approaches, and discuss several issues associated with futility analyses, such as ethical considerations, whether or not type I error can or should be reclaimed, one-sided vs two-sided futility rules, and the impact of futility analyses on power.

MeSH terms

  • Clinical Trials as Topic / methods*
  • Data Interpretation, Statistical
  • Endpoint Determination
  • Ethics, Medical
  • Evaluation Studies as Topic
  • Humans
  • Models, Statistical
  • Multicenter Studies as Topic
  • Myocardial Infarction / drug therapy
  • Probability
  • Randomized Controlled Trials as Topic
  • Research Design*
  • Sample Size
  • Stochastic Processes
  • Time Factors