Accounting for between-study variation in incremental net benefit in value of information methodology

Health Econ. 2012 Oct;21(10):1183-95. doi: 10.1002/hec.1781. Epub 2011 Sep 1.


Previous applications of value of information methods for determining optimal sample size in randomized clinical trials have assumed no between-study variation in mean incremental net benefit. By adopting a hierarchical model, we provide a solution for determining optimal sample size with this assumption relaxed. The solution is illustrated with two examples from the literature. Expected net gain increases with increasing between-study variation, reflecting the increased uncertainty in incremental net benefit and reduced extent to which data are borrowed from previous evidence. Hence, a trial can become optimal where current evidence is sufficient assuming no between-study variation. However, despite the expected net gain increasing, the optimal sample size in the illustrated examples is relatively insensitive to the amount of between-study variation. Further percentage losses in expected net gain were small even when choosing sample sizes that reflected widely different between-study variation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cesarean Section / economics
  • Cost-Benefit Analysis
  • Female
  • Humans
  • Models, Economic
  • Pregnancy
  • Randomized Controlled Trials as Topic / economics
  • Randomized Controlled Trials as Topic / methods*
  • Reproducibility of Results
  • Research Design*
  • Sample Size*
  • Version, Fetal / economics